Influence of backside seating parameters and augmented baseplate components in virtual planning for reverse shoulder arthroplasty

BACKGROUND

The primary goal of this investigation was to examine the influence of a backside seating percentage variable on volume of reamed bone and contact area in virtual planning for glenoid baseplate placement for reverse total shoulder arthroplasty (RTSA). The secondary goal was to assess how the option of augmented glenoid baseplate components affected reamed volume and cortical contact area of virtually positioned baseplates.

METHODS

Nine surgeons virtually planned 30 RTSA cases using a commercially available software system. The 30 cases were chosen to span a spectrum of glenoid deformity. The study consisted of 3 phases. In phase 1, cases were planned with the backside seating percentage blinded and without the option of augmented baseplate components. In phase 2, the backside seating parameter was unblinded. In phase 3, augmented baseplate components were added as an option. Implant version and inclination were recorded. By use of computer-assisted design models, total volume of bone reamed, as well as reamed cortical volume and cancellous volume, was calculated. Total, cortical, and cancellous baseplate contact areas were also calculated. Finally, total glenoid lateralization was calculated for each phase and compared.

RESULTS

Mean implant version was clinically similar across phases but was statistically significantly lower in phase 3 (P = .006 compared with phase 1 and P = .001 compared with phase 2). Mean implant inclination was clinically similar across phases but was statistically significantly lower in phase 3 (P < .001). Phase 3 had statistically significantly lower cancellous and total reamed bone volumes compared with phase 1 and phase 2 (P < .001 for all comparisons). Phase 3 had statistically significantly larger cortical contact area, lower cancellous contact area, and larger total contact area compared with phase 1 and phase 2 (P < .001 for all comparisons). Phase 3 had significantly greater glenoid lateralization (mean, 10.5 mm) compared with phase 1 (mean, 7.8 mm; P < .001) and phase 2 (mean, 7.9 mm; P < .001).

CONCLUSIONS

Across a wide range of glenoid pathology during virtual surgical planning, experienced shoulder arthroplasty surgeons chose augmented baseplates frequently, and the option of a full-wedge augmented baseplate resulted in statistically significantly greater correction of glenoid deformity, improved total and cortical baseplate contact area, less cancellous reamed bone, and greater glenoid lateralization. Backside seating information does not have a significant impact on how glenoid baseplates are virtually positioned for RTSA, nor does it impact the baseplate contact area or volume of reamed bone.

Meniscal and Articular Cartilage Predictors of Outcome After Revision ACL Reconstruction: A 6-Year Follow-up Cohort Study

BACKGROUND

Meniscal and chondral damage is common in the patient undergoing revision anterior cruciate ligament (ACL) reconstruction.

PURPOSE

To determine if meniscal and/or articular cartilage pathology at the time of revision ACL surgery significantly influences a patient's outcome at 6-year follow-up.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Patients undergoing revision ACL reconstruction were prospectively enrolled between 2006 and 2011. Data collection included baseline demographics, surgical technique, pathology, treatment, and scores from 4 validated patient-reported outcome instruments: International Knee Documentation Committee (IKDC), Knee injury and Osteoarthritis Outcome Score (KOOS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Marx Activity Rating Scale. Patients were followed up at 6 years and asked to complete the identical set of outcome instruments. Regression analysis assessed the meniscal and articular cartilage pathology risk factors for clinical outcomes 6 years after revision ACL reconstruction.

RESULTS

An overall 1234 patients were enrolled (716 males, 58%; median age, 26 years). Surgeons reported the pathology at the time of revision surgery in the medial meniscus (45%), lateral meniscus (36%), medial femoral condyle (43%), lateral femoral condyle (29%), medial tibial plateau (11%), lateral tibial plateau (17%), patella (30%), and trochlea (21%). Six-year follow-up was obtained on 79% of the sample (980/1234). Meniscal pathology and articular cartilage pathology (medial femoral condyle, lateral femoral condyle, lateral tibial plateau, trochlea, and patella) were significant drivers of poorer patient-reported outcomes at 6 years (IKDC, KOOS, WOMAC, and Marx). The most consistent factors driving outcomes were having a medial meniscal excision (either before or at the time of revision surgery) and patellofemoral articular cartilage pathology. Six-year Marx activity levels were negatively affected by having either a repair/excision of the medial meniscus (odds ratio range, 1.45-1.72; P≤ .04) or grade 3-4 patellar chondrosis (odds ratio, 1.72; P = .04). Meniscal pathology occurring before the index revision surgery negatively affected scores on all KOOS subscales except for sports/recreation (P < .05). Articular cartilage pathology significantly impaired all KOOS subscale scores (P < .05). Lower baseline outcome scores, higher body mass index, being a smoker, and incurring subsequent surgery all significantly increased the odds of reporting poorer clinical outcomes at 6 years.

CONCLUSION

Meniscal and chondral pathology at the time of revision ACL reconstruction has continued significant detrimental effects on patient-reported outcomes at 6 years after revision surgery.

Short-term clinical and radiographic outcomes of a hybrid all-polyethylene glenoid based on preoperative glenoid morphology

BACKGROUND

The primary purpose of this study was to compare 2-year anatomic total shoulder arthroplasty (TSA) functional and radiographic outcomes between Walch type A and B glenoids treated with an all-polyethylene glenoid designed for hybrid fixation with peripheral cement and central osseous integration. The secondary purpose was to evaluate outcomes based on central peg technique. The hypotheses were that there would be no difference in short-term radiographic or functional outcome scores based on preoperative glenoid morphology or central peg technique.

METHODS

We performed a multicenter retrospective review of patients who underwent TSA with the same hybrid all-polyethylene glenoid and had minimum 2-year follow-up. Patient-reported outcomes and radiographic outcomes were analyzed based on preoperative Walch morphology and central peg technique. Radiographic analysis included preoperative glenoid morphology; preoperative and postoperative glenoid version, glenoid inclination, and posterior humeral head subluxation; and postoperative glenoid radiolucencies according to the Wirth and Lazarus classifications.

RESULTS

A total of 266 patients with a mean age of 64.9 ± 8.2 years were evaluated at a mean of 28 months postoperatively. Postoperatively, there were significant improvements in all functional outcome measures (P < .001), range-of-motion measures (forward elevation, external rotation at 0°, external rotation at 90°, internal rotation by spinal level, and internal rotation at 90°; P < .001), and strength measures (Constant, external rotation, and modified belly press; P < .001). There were no clinically meaningful differences in functional outcomes or statistically significant differences in radiographic appearance between Walch type A and B glenoids. Subgroup analysis revealed that glenoids with a cemented central peg had the worst radiographic outcomes based on Lazarus scoring.

CONCLUSION

Patients undergoing TSA with a hybrid in-line pegged glenoid have excellent clinical outcomes at short-term follow-up regardless of preoperative glenoid morphology. Different central peg techniques do not appear to play a significant role in the risk of glenoid component lucencies at 2 years postoperatively.

Prescribing Fewer Opioids After Rotator Cuff Repair and Anterior Cruciate Ligament Reconstruction Lowers Opioid Consumption Without Impacting Patient-Reported Pain Scores

Purpose

To develop a standardized opioid prescribing schedule (SOPS) following anterior cruciate ligament reconstruction (ACLR) and rotator cuff repair (RCR) and evaluate postoperative opioid consumption alongside Patient-Reported Outcome Measurement Information System (PROMIS) pain interference scores.

Methods

A prospective observational study was performed on all patients undergoing primary ACLR and RCR from March 2019 to October 2021. Patients taking opioids preoperatively and revision ACLR and RCR were excluded. PROMIS 6B questionnaires were administered before and after implantation of the SOPS initiated on December 15, 2019. Opioid consumption was determined by email surveys. Hypothesis testing was performed with Mann–Whitney U test.

Results

A total of 599 patients met inclusion criteria with 188 patients (71 ACLR and 117 RCR) completing surveys. Before the initiation of SOPS, the average number of oxycodone 5-mg tablets prescribed for ACLR was 44.6 (95% confidence interval [CI] 42.4-46.9) and for RCR was 44.7 (95% CI 42.7-46.8). The average usage was 23.1 (95% CI 16.9-29.2) and 22.1 (95% CI 16.2-28.0), respectively. Following SOPS of 30 tablets of oxycodone 5 mg for ACLR and 40 tablets for RCR, the average number of tablets prescribed significantly decreased for both procedures (P < .01 for ACLR and RCR), and the average consumption decreased to 20.5 (95% CI 16.6-24.4) and 18.6 (95% CI 14.6-22.5), respectively. PROMIS 6B responses did not demonstrate statistically significant changes following SOPS.

Conclusions

The results of the present study demonstrate that the implementation of a SOPS reduced postoperative opioid prescribing amounts and consumption without significant impacting PROMIS pain interference scores for ACLR and RCR, supporting the possibility to decrease and standardize opioid prescribing following common sports medicine procedures.

Level of Evidence

III: Retrospective, comparative, therapeutic study.

Descriptive Characteristics and Outcomes of Patients Undergoing Revision Anterior Cruciate Ligament Reconstruction With and Without Tunnel Bone Grafting

BACKGROUND

Lytic or malpositioned tunnels may require bone grafting during revision anterior cruciate ligament reconstruction (rACLR) surgery. Patient characteristics and effects of grafting on outcomes after rACLR are not well described.

PURPOSE

To describe preoperative characteristics, intraoperative findings, and 2-year outcomes for patients with rACLR undergoing bone grafting procedures compared with patients with rACLR without grafting.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 1234 patients who underwent rACLR were prospectively enrolled between 2006 and 2011. Baseline revision and 2-year characteristics, surgical technique, pathology, treatment, and patient-reported outcome instruments (International Knee Documentation Committee [IKDC], Knee injury and Osteoarthritis Outcome Score [KOOS], Western Ontario and McMaster Universities Osteoarthritis Index, and Marx Activity Rating Scale [Marx]) were collected, as well as subsequent surgery information, if applicable. The chi-square and analysis of variance tests were used to compare group characteristics.

RESULTS

A total of 159 patients (13%) underwent tunnel grafting-64 (5%) patients underwent 1-stage and 95 (8%) underwent 2-stage grafting. Grafting was isolated to the femur in 31 (2.5%) patients, the tibia in 40 (3%) patients, and combined in 88 patients (7%). Baseline KOOS Quality of Life (QoL) and Marx activity scores were significantly lower in the 2-stage group compared with the no bone grafting group (P≤ .001). Patients who required 2-stage grafting had more previous ACLRs (P < .001) and were less likely to have received a bone-patellar tendon-bone or a soft tissue autograft at primary ACLR procedure (P≤ .021) compared with the no bone grafting group. For current rACLR, patients undergoing either 1-stage or 2-stage bone grafting were more likely to receive a bone-patellar tendon-bone allograft (P≤ .008) and less likely to receive a soft tissue autograft (P≤ .003) compared with the no bone grafting group. At 2-year follow-up of 1052 (85%) patients, we found inferior outcomes in the 2-stage bone grafting group (IKDC score = 68; KOOS QoL score = 44; KOOS Sport/Recreation score = 65; and Marx activity score = 3) compared with the no bone grafting group (IKDC score = 77; KOOS QoL score = 63; KOOS Sport/Recreation score = 75; and Marx activity score = 7) (P≤ .01). The 1-stage bone graft group did not significantly differ compared with the no bone grafting group.

CONCLUSION

Tunnel bone grafting was performed in 13% of our rACLR cohort, with 8% undergoing 2-stage surgery. Patients treated with 2-stage grafting had inferior baseline and 2-year patient-reported outcomes and activity levels compared with patients not undergoing bone grafting. Patients treated with 1-stage grafting had similar baseline and 2-year patient-reported outcomes and activity levels compared with patients not undergoing bone grafting.

Returning to Activity After Anterior Cruciate Ligament Revision Surgery: An Analysis of the Multicenter Anterior Cruciate Ligament Revision Study (MARS) Cohort at 2 Years Postoperative

BACKGROUND

Patients with anterior cruciate ligament (ACL) revision report lower outcome scores on validated knee questionnaires postoperatively compared to cohorts with primary ACL reconstruction. In a previously active population, it is unclear if patient-reported outcomes (PROs) are associated with a return to activity (RTA) or vary by sports participation level (higher level vs. recreational athletes).

HYPOTHESES

Individual RTA would be associated with improved outcomes (ie, decreased knee symptoms, pain, function) as measured using validated PROs. Recreational participants would report lower PROs compared with higher level athletes and be less likely to RTA.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

There were 862 patients who underwent a revision ACL reconstruction (rACLR) and self-reported physical activity at any level preoperatively. Those who did not RTA reported no activity 2 years after revision. Baseline data included patient characteristics, surgical history and characteristics, and PROs: International Knee Documentation Committee questionnaire, Marx Activity Rating Scale, Knee injury and Osteoarthritis Outcome Score, and the Western Ontario and McMaster Universities Osteoarthritis Index. A binary indicator was used to identify patients with same/better PROs versus worse outcomes compared with baseline, quantifying the magnitude of change in each direction, respectively. Multivariable regression models were used to evaluate risk factors for not returning to activity, the association of 2-year PROs after rACLR surgery by RTA status, and whether each PRO and RTA status differed by participation level.

RESULTS

At 2 years postoperatively, approximately 15% did not RTA, with current smokers (adjusted odds ratio [aOR] = 3.3; P = .001), female patients (aOR = 2.9; P < .001), recreational participants (aOR = 2.0; P = .016), and those with a previous medial meniscal excision (aOR = 1.9; P = .013) having higher odds of not returning. In multivariate models, not returning to activity was significantly associated with having worse PROs at 2 years; however, no clinically meaningful differences in PROs at 2 years were seen between participation levels.

CONCLUSION

Recreational-level participants were twice as likely to not RTA compared with those participating at higher levels. Within a previously active cohort, no RTA was a significant predictor of lower PROs after rACLR. However, among patients who did RTA after rACLR, approximately 20% reported lower outcome scores. Most patients with rACLR who were active at baseline improved over time; however, patients who reported worse outcomes at 2 years had a clinically meaningful decline across all PROs.

Glenohumeral Hydrodistension for Postoperative Stiffness After Arthroscopic Primary Rotator Cuff Repair

Background:

Postoperative stiffness is a known complication after rotator cuff repair (RCR). Glenohumeral hydrodistension (GH) has been a treatment modality for shoulder pathology but has not been used to treat postoperative stiffness after RCR.

Purpose/Hypothesis:

The purpose of this study was to identify the risk factors for postoperative stiffness after RCR and review outcomes after treatment with GH. Our hypotheses were that stiffness would be associated with diabetes and hyperlipidemia and correlated with the tendons involved and that patients with stiffness who underwent GH would have significant improvement in range of motion (ROM).

Study Design:

Case series; Level of evidence, 4.

Methods:

Included were 388 shoulders of patients who underwent primary RCR by a single surgeon between 2015 and 2019. Shoulders with revision RCRs were excluded. Patient characteristics, medical comorbidities, and perioperative details were collected. A total of 40 shoulders with postoperative stiffness (10.3%) received GH injectate of a 21-mL mixture (15 mL of sterile water, 5 mL of 0.5% ropivacaine, and 1 mL of triamcinolone [10 mg/mL]). The primary outcome measure was ROM in forward flexion, internal rotation, external rotation, and abduction. Statistical tests were performed using analysis of variance.

Results:

Patients with diabetes had significantly decreased internal rotation at final follow-up after RCR as compared with patients without diabetes. GH to treat stiffness was performed most commonly between 1 and 4 months after RCR (60%), and patients who received GH saw statistically significant improvements in forward flexion, external rotation, and abduction after the procedure. Patients with hyperlipidemia had the most benefit after GH. Among those undergoing concomitant procedures, significantly more patients who had open subpectoral biceps tenodesis underwent GH. Patients who underwent subscapularis repair or concomitant subacromial decompression had significant improvement in ROM after GH. Only 1 patient who received GH underwent secondary surgery for resistant postoperative stiffness.

Conclusion:

Patients with diabetes had increased stiffness. Patients with a history of hyperlipidemia or concomitant open subpectoral biceps tenodesis were more likely to undergo GH for postoperative stiffness. Patients who underwent subscapularis repair demonstrated the most improvement in ROM after GH. After primary RCR, GH can increase ROM and is a useful adjunct for patients with stiffness to limit secondary surgery.

Computational Metrics Can Provide Quantitative Values to Characterize Arthroscopic Field of View

Purpose

The purpose of this study was to determine the inter-rater reliability of arthroscopic video quality, determine correlation between surgeon rating and computational image metrics, and facilitate a quantitative methodology for assessing video quality.

Methods

Five orthopaedic surgeons reviewed 60 clips from deidentified arthroscopic shoulder videos and rated each on a four-point Likert scale from poor to excellent view. The videos were randomized, and the process was completed a total of three times. Each user rating was averaged to provide a user rating per clip. Each video frame was processed to calculate brightness, local contrast, redness (used to represent bleeding), and image entropy. Each metric was then averaged over each frame per video clip, providing four image quality metrics per clip.

Results

Inter-rater reliability for grading video quality had an intraclass correlation of .974. Improved image quality rating was positively correlated with increased entropy (.8142; P < .001), contrast (.8013; P < .001), and brightness (.6120; P < .001), and negatively correlated with redness (−.8626; P < .001). A multiple linear regression model was calculated with the image metrics used as predictors for the image quality ranking, with an R-squared value of .775 and root mean square error of .42.

Conclusions

Our study demonstrates strong inter-rater reliability between surgeons when describing image quality and strong correlations between image quality and the computed image metrics. A model based on these metrics enables automatic quantification of image quality.

Clinical Relevance

Video quality during arthroscopic cases can impact the ease and duration of the case which could contribute to swelling and complication risk. This pilot study provides a quantitative method to assess video quality. Future works can objectively determine factors that affect visualization during arthroscopy and identify options for improvement.

Changes in Infrapatellar Fat Pad Volume 6 to 12 Months After Anterior Cruciate Ligament Reconstruction and Associations With Patient-Reported Knee Function

CONTEXT

Hypertrophy of the infrapatellar fat pad (IFP) in idiopathic knee osteoarthritis has been linked to deleterious synovial changes and joint pain related to mechanical tissue impingement. Yet little is known regarding the IFP's volumetric changes after anterior cruciate ligament reconstruction (ACLR).

OBJECTIVES

To examine changes in IFP volume between 6 and 12 months after ACLR and determine associations between patient-reported outcomes and IFP volume at each time point as well as the volume change over time. In a subset of individuals, we examined interlimb IFP volume differences 12 months post-ACLR.

STUDY DESIGN

Prospective cohort study.

SETTING

Laboratory.

PATIENTS OR OTHER PARTICIPANTS

We studied 26 participants (13 women, 13 men, age = 21.88 ± 3.58 years, body mass index = 23.82 ± 2.21 kg/m2) for our primary aims and 13 of those participants (8 women, 5 men, age = 21.15 ± 3.85 years, body mass index = 23.01 ± 2.01 kg/m2) for our exploratory aim.

MAIN OUTCOME MEASURE(S)

Using magnetic resonance imaging, we evaluated the IFP volume change between 6 and 12 months post-ACLR in the ACLR limb and between-limbs differences at 12 months in a subset of participants. International Knee Documentation Committee subjective knee evaluation (IKDC) scores were collected at 6-month and 12-month follow-ups, and associations between IFP volume and patient-reported outcomes were determined.

RESULTS

The IFP volume in the ACLR limb increased from 6 months (19.67 ± 6.30 cm3) to 12 months (21.26 ± 6.91 cm3) post-ACLR. Greater increases of IFP volume between 6 and 12 months were significantly associated with better 6-month IKDC scores (r = .44, P = .03). The IFP volume was greater in the uninjured limb (22.71 ± 7.87 cm3) than in the ACLR limb (20.75 ± 9.03 cm3) 12 months post-ACLR.

CONCLUSIONS

The IFP volume increased between 6 and 12 months post-ACLR; however, the IFP volume of the ACLR limb remained smaller than that of the uninjured limb at 12 months. In addition, those with better knee function 6 months post-ACLR demonstrated greater increases in IFP volume between 6 and 12 months post-ACLR. This suggests that greater IFP volumes may play a role in long-term joint health after ACLR.

Clinical and Radiological Outcomes in Reverse Total Shoulder Arthroplasty by Inclination Angle With a Modular Prosthesis

The influence of the humeral inclination in reverse total shoulder arthroplasty (RTSA) is not well understood. The purpose of this study was to determine outcomes and complications after RTSA with an inclination of 135° or 155° in a modular prosthesis. American Shoulder and Elbow Surgeons (ASES), visual analog scale (VAS), Single Assessment Numeric Evaluation (SANE), and Simple Shoulder Test (SST) scores, as well as forward elevation (FE), abduction (ABD), and external rotation (ER), were assessed after a minimum 2-year follow-up. Scapular notching and radiolucency were assessed according to Sirveaux and Lévigne. A total of 121 patients with a mean age of 69.7±7.3 years were evaluated after a mean of 36.5±8 months. The inclination was set to 135° in 80.2% and to 155° in 19.8% of patients. There was no significant difference between the groups for ASES, VAS, SANE, and SST scores. The FE (P=.022) and ABD (P=.002) were significantly higher for the 155° inclination group. Complication rates were not significantly different between the groups. Scapular notching was significantly more common with a 155° inclination (P=.01), whereas humeral radiolucency was not correlated. All outcome scores improved significantly from pre- to postoperative (P≤.001). Reverse total shoulder arthroplasty leads to significant improvements in pain, range of motion, and outcome scores after mid-term follow-up. Overall, the inclination angle does not significantly affect clinical outcomes or the complication rate after RTSA at mid-term follow-up. However, an inclination of 155° shows significantly greater FE and ABD, although it results in a significantly higher rate of scapular notching. Cases with scapular notching are associated with significantly reduced mean ASES scores and ER as well as significantly higher VAS scores. [Orthopedics. 2021;44(4):e527-e533.].

Association Between Graft Choice and 6-Year Outcomes of Revision Anterior Cruciate Ligament Reconstruction in the MARS Cohort

BACKGROUND

Although graft choice may be limited in the revision setting based on previously used grafts, most surgeons believe that graft choice for anterior cruciate ligament (ACL) reconstruction is an important factor related to outcome.

HYPOTHESIS

In the ACL revision setting, there would be no difference between autograft and allograft in rerupture rate and patient-reported outcomes (PROs) at 6-year follow-up.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Patients who had revision surgery were identified and prospectively enrolled in this cohort study by 83 surgeons over 52 sites. Data collected included baseline characteristics, surgical technique and pathology, and a series of validated PRO measures. Patients were followed up at 6 years and asked to complete the identical set of PRO instruments. Incidence of additional surgery and reoperation because of graft failure were also recorded. Multivariable regression models were used to determine the predictors (risk factors) of PROs, graft rerupture, and reoperation at 6 years after revision surgery.

RESULTS

A total of 1234 patients including 716 (58%) men were enrolled. A total of 325 (26%) underwent revision using a bone-patellar tendon-bone (BTB) autograft; 251 (20%), soft tissue autograft; 289 (23%), BTB allograft; 302 (25%), soft tissue allograft; and 67 (5%), other graft. Questionnaires and telephone follow-up for subsequent surgery information were obtained for 809 (66%) patients, while telephone follow-up was only obtained for an additional 128 patients for the total follow-up on 949 (77%) patients. Graft choice was a significant predictor of 6-year Marx Activity Rating Scale scores (P = .024). Specifically, patients who received a BTB autograft for revision reconstruction had higher activity levels than did patients who received a BTB allograft (odds ratio [OR], 1.92; 95% CI, 1.25-2.94). Graft rerupture was reported in 5.8% (55/949) of patients by their 6-year follow-up: 3.5% (16/455) of patients with autografts and 8.4% (37/441) of patients with allografts. Use of a BTB autograft for revision resulted in patients being 4.2 times less likely to sustain a subsequent graft rupture than if a BTB allograft were utilized (P = .011; 95% CI, 1.56-11.27). No significant differences were found in graft rerupture rates between BTB autograft and soft tissue autografts (P = .87) or between BTB autografts and soft tissue allografts (P = .36). Use of an autograft was found to be a significant predictor of having fewer reoperations within 6 years compared with using an allograft (P = .010; OR, 0.56; 95% CI, 0.36-0.87).

CONCLUSION

BTB and soft tissue autografts had a decreased risk in graft rerupture compared with BTB allografts. BTB autografts were associated with higher activity level than were BTB allografts at 6 years after revision reconstruction. Surgeons and patients should consider this information when choosing a graft for revision ACL reconstruction.

Synovial fluid concentrations of matrix Metalloproteinase-3 and Interluekin-6 following anterior cruciate ligament injury associate with gait biomechanics 6 months following reconstruction

OBJECTIVE

To compare gait biomechanics 6 months following anterior cruciate ligament (ACL) reconstruction (ACLR) between patients with the highest and lowest concentrations of synovial fluid (SF) interleukin-6 (IL-6) and matrix metalloproteinase-3 (MMP-3), as well as compared to uninjured controls.

DESIGN

SF concentrations of IL-6 and MMP-3 were collected 7 ± 4 days post injury in 38 ACL injured patients (55% female, 21±4yrs, 25.3 ± 5.2BMI). ACL injured individuals were stratified into the lowest and highest quartiles based on IL-6 (IL-6_Lowest and IL-6_Highest) and MMP-3 (MMP-3_Lowest and MMP-3_Highest) concentrations. Gait biomechanics were collected on the injured limb 6 months post-ACLR and in 38 uninjured controls (50% female, 21±3yrs, 23.8 ± 2.8BMI). Functional analyses of variance were used to compare vertical ground reaction force (vGRF), knee flexion angle (KFA), and internal knee extension moment (KEM) waveforms throughout stance phase of gait to determine the proportions of stance differing between limbs and groups.

RESULTS

Compared to uninjured controls, IL-6_High and MMP-3_High ACL subgroups demonstrated lesser vGRF (largest differences: IL-6, 7.88%BW; MMP-3, 11.05%BW) during early-stance and greater vGRF (largest differences: IL-6, 6.21%BW; MMP-3, 5.85%BW) in mid-stance, lesser KFA (largest differences: IL-6, 3.11°; MMP-3, 3.72°) and lesser KEM (largest differences: IL-6, 0.96%BW•m; MMP-3, 1.07%BW•m) in early-stance, as well as greater KFA in mid-stance (largest differences: IL-6, 1.5°; MMP-3, 2.95°).

CONCLUSIONS

High SF concentrations of a proinflammatory cytokine and a degradative enzyme early post-ACL injury are associated with aberrant gait biomechanics in the injured limb at 6 months post-ACLR (i.e., lesser vGRF, KFA and KEM) linked to posttraumatic osteoarthritis development.

Gait Biomechanics in Individuals Meeting Sufficient Quadriceps Strength Cutoffs Following Anterior Cruciate Ligament Reconstruction

CONTEXT

Quadriceps weakness is associated with disability and aberrant gait biomechanics following anterior cruciate ligament reconstruction (ACLR). Strength sufficiency cutoff scores, that normalize quadriceps strength to the mass of an individual, are capable of predicting individuals who will report better function following ACLR. Yet, it remains unknown if gait biomechanics differ between individuals who meet a strength sufficiency cutoff (strong) compared to those who do not (weak).

OBJECTIVE

Determine if vertical ground reaction force (vGRF), knee flexion angle (KFA) and internal knee extension moment (KEM) differ between strong and weak individuals with an ACLR throughout stance phase of walking.

DESIGN

Comparison-control.

SETTING

Laboratory Participants: Individuals who received unilateral ACLR ≥12 months prior to testing were dichotomized into strong (n=31) and weak groups (n=116).

MAIN OUTCOME MEASURES

Maximal isometric quadriceps strength was collected at 90° of knee flexion using an isokinetic dynamometer and normalized to body mass. Individuals demonstrating ≥3.0Nm/kg were considered strong. Three-dimensional gait biomechanics were collected at a self-selected walking speed. Biomechanical data were time-normalized to 100% of stance phase. vGRF were normalized to body weight (BW), and KEM was normalized to BW*height. Pairwise comparison functions were calculated for each outcome to identify between-group differences for each percentile of stance.

RESULTS

vGRF was significantly greater in weak participants for the first 22% of stance (average difference of 6.2% BW) and lesser in weak participants between 36-43% of stance (1.4% BW). KFA was significantly greater (i.e., more flexion) in strong participants between 6-62% of stance (2.3°) and lesser (i.e., less flexion) between 68-79% of stance (1.0°). KEM was significantly greater in strong participants between 7-62% of stance (0.007 BW*height).

CONCLUSIONS

ACLR individuals able to generate knee extension torque ≥3.0Nm/kg exhibit different biomechanical gait profiles compared to weak individuals, which may allow for better energy attenuation following ACLR.

Meniscal Repair in the Setting of Revision Anterior Cruciate Ligament Reconstruction: Results From the MARS Cohort

BACKGROUND

Meniscal preservation has been demonstrated to contribute to long-term knee health. This has been a successful intervention in patients with isolated tears and tears associated with anterior cruciate ligament (ACL) reconstruction. However, the results of meniscal repair in the setting of revision ACL reconstruction have not been documented.

PURPOSE

To examine the prevalence and 2-year operative success rate of meniscal repairs in the revision ACL setting.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

All cases of revision ACL reconstruction with concomitant meniscal repair from a multicenter group between 2006 and 2011 were selected. Two-year follow-up was obtained by phone and email to determine whether any subsequent surgery had occurred to either knee since the initial revision ACL reconstruction. If so, operative reports were obtained, whenever possible, to verify the pathologic condition and subsequent treatment.

RESULTS

In total, 218 patients (18%) from 1205 revision ACL reconstructions underwent concurrent meniscal repairs. There were 235 repairs performed: 153 medial, 48 lateral, and 17 medial and lateral. The majority of these repairs (n = 178; 76%) were performed with all-inside techniques. Two-year surgical follow-up was obtained on 90% (197/218) of the cohort. Overall, the meniscal repair failure rate was 8.6% (17/197) at 2 years. Of the 17 failures, 15 were medial (13 all-inside, 2 inside-out) and 2 were lateral (both all-inside). Four medial failures were treated in conjunction with a subsequent repeat revision ACL reconstruction.

CONCLUSION

Meniscal repair in the revision ACL reconstruction setting does not have a high failure rate at 2-year follow-up. Failure rates for medial and lateral repairs were both <10% and consistent with success rates of primary ACL reconstruction meniscal repair. Medial tears underwent reoperation for failure at a significantly higher rate than lateral tears.

Predictors of Patient-Reported Outcomes at 2 Years After Revision Anterior Cruciate Ligament Reconstruction

BACKGROUND

Patient-reported outcomes (PROs) are a valid measure of results after revision anterior cruciate ligament (ACL) reconstruction. Revision ACL reconstruction has been documented to have worse outcomes when compared with primary ACL reconstruction. Understanding positive and negative predictors of PROs will allow surgeons to modify and potentially improve outcome for patients.

PURPOSE/HYPOTHESIS

The purpose was to describe PROs after revision ACL reconstruction and test the hypothesis that patient- and technique-specific variables are associated with these outcomes.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Patients undergoing revision ACL reconstruction were identified and prospectively enrolled by 83 surgeons over 52 sites. Data included baseline demographics, surgical technique and pathology, and a series of validated PRO instruments: International Knee Documentation Committee (IKDC), Knee injury and Osteoarthritis Outcome Score (KOOS), Western Ontario and McMaster Universities Osteoarthritis Index, and Marx Activity Rating Scale. Patients were followed up at 2 years and asked to complete the identical set of outcome instruments. Multivariate regression models were used to control for a variety of demographic and surgical factors to determine the positive and negative predictors of PRO scores at 2 years after revision surgery.

RESULTS

A total of 1205 patients met the inclusion criteria and were successfully enrolled: 697 (58%) were male, with a median cohort age of 26 years. The median time since their most recent previous ACL reconstruction was 3.4 years. Two-year questionnaire follow-up was obtained from 989 patients (82%). The most significant positive predictors of 2-year IKDC scores were a high baseline IKDC score, high baseline Marx activity level, male sex, and having a longer time since the most recent previous ACL reconstruction, while negative predictors included having a lateral meniscectomy before the revision ACL reconstruction or having grade 3/4 chondrosis in either the trochlear groove or the medial tibial plateau at the time of the revision surgery. For KOOS, having a high baseline score and having a longer time between the most recent previous ACL reconstruction and revision surgery were significant positive predictors for having a better (ie, higher) 2-year KOOS, while having a lateral meniscectomy before the revision ACL reconstruction was a consistent predictor for having a significantly worse (ie, lower) 2-year KOOS. Statistically significant positive predictors for 2-year Marx activity levels included higher baseline Marx activity levels, younger age, male sex, and being a nonsmoker. Negative 2-year activity level predictors included having an allograft or a biologic enhancement at the time of revision surgery.

CONCLUSION

PROs after revision ACL reconstruction are associated with a variety of patient- and surgeon-related variables. Understanding positive and negative predictors of PROs will allow surgeons to guide patient expectations as well as potentially improve outcomes.

Relationship Between Sports Participation After Revision Anterior Cruciate Ligament Reconstruction and 2-Year Patient-Reported Outcome Measures

BACKGROUND

Anterior cruciate ligament (ACL) revision cohorts continually report lower outcome scores on validated knee questionnaires than primary ACL cohorts at similar time points after surgery. It is unclear how these outcomes are associated with physical activity after physician clearance for return to recreational or competitive sports after ACL revision surgery.

HYPOTHESES

Participants who return to either multiple sports or a singular sport after revision ACL surgery will report decreased knee symptoms, increased activity level, and improved knee function as measured by validated patient-reported outcome measures (PROMs) and compared with no sports participation. Multisport participation as compared with singular sport participation will result in similar increased PROMs and activity level.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A total of 1205 patients who underwent revision ACL reconstruction were enrolled by 83 surgeons at 52 clinical sites. At the time of revision, baseline data collected included the following: demographics, surgical characteristics, previous knee treatment and PROMs, the International Knee Documentation Committee (IKDC) questionnaire, Marx activity score, Knee injury and Osteoarthritis Outcome Score (KOOS), and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). A series of multivariate regression models were used to evaluate the association of IKDC, KOOS, WOMAC, and Marx Activity Rating Scale scores at 2 years after revision surgery by sports participation category, controlling for known significant covariates.

RESULTS

Two-year follow-up was obtained on 82% (986 of 1205) of the original cohort. Patients who reported not participating in sports after revision surgery had lower median PROMs both at baseline and at 2 years as compared with patients who participated in either a single sport or multiple sports. Significant differences were found in the change of scores among groups on the IKDC (P < .0001), KOOS-Symptoms (P = .01), KOOS-Sports and Recreation (P = .04), and KOOS-Quality of Life (P < .0001). Patients with no sports participation were 2.0 to 5.7 times more likely than multiple-sport participants to report significantly lower PROMs, depending on the specific outcome measure assessed, and 1.8 to 3.8 times more likely than single-sport participants (except for WOMAC-Stiffness, P = .18), after controlling for known covariates.

CONCLUSION

Participation in either a single sport or multiple sports in the 2 years after ACL revision surgery was found to be significantly associated with higher PROMs across multiple validated self-reported assessment tools. During follow-up appointments, surgeons should continue to expect that patients who report returning to physical activity after surgery will self-report better functional outcomes, regardless of baseline activity levels.

Physiologic Preoperative Knee Hyperextension Is a Predictor of Failure in an Anterior Cruciate Ligament Revision Cohort: A Report From the MARS Group

BACKGROUND

The occurrence of physiologic knee hyperextension (HE) in the revision anterior cruciate ligament reconstruction (ACLR) population and its effect on outcomes have yet to be reported. Hypothesis/Purpose: The prevalence of knee HE in revision ACLR and its effect on 2-year outcome were studied with the hypothesis that preoperative physiologic knee HE ≥5° is a risk factor for anterior cruciate ligament (ACL) graft rupture.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Patients undergoing revision ACLR were identified and prospectively enrolled between 2006 and 2011. Study inclusion criteria were patients undergoing single-bundle graft reconstructions. Patients were followed up at 2 years and asked to complete an identical set of outcome instruments (International Knee Documentation Committee, Knee injury and Osteoarthritis Outcome Score, WOMAC, and Marx Activity Rating Scale) as well as provide information regarding revision ACL graft failure. A regression model with graft failure as the dependent variable included age, sex, graft type at the time of the revision ACL surgery, and physiologic preoperative passive HE ≥5° (yes/no) to assess these as potential risk factors for clinical outcomes 2 years after revision ACLR.

RESULTS

Analyses included 1145 patients, for whom 2-year follow-up was attained for 91%. The median age was 26 years, with age being a continuous variable. Those below the median were grouped as "younger" and those above as "older" (age: interquartile range = 20, 35 years), and 42% of patients were female. There were 50% autografts, 48% allografts, and 2% that had a combination of autograft plus allograft. Passive knee HE ≥5° was present in 374 (33%) patients in the revision cohort, with 52% being female. Graft rupture at 2-year follow-up occurred in 34 cases in the entire cohort, of which 12 were in the HE ≥5° group (3.2% failure rate) and 22 in the non-HE group (2.9% failure rate). The median age of patients who failed was 19 years, as opposed to 26 years for those with intact grafts. Three variables in the regression model were significant predictors of graft failure: younger age (odds ratio [OR] = 3.6; 95% CI, 1.6-7.9; P = .002), use of allograft (OR = 3.3; 95% CI, 1.5-7.4; P = .003), and HE ≥5° (OR = 2.12; 95% CI, 1.1-4.7; P = .03).

CONCLUSION

This study revealed that preoperative physiologic passive knee HE ≥5° is present in one-third of patients who undergo revision ACLR. HE ≥5° was an independent significant predictor of graft failure after revision ACLR with a >2-fold OR of subsequent graft rupture in revision ACL surgery. Registration: NCT00625885 ( ClinicalTrials.gov identifier).

Time between anterior cruciate ligament injury and reconstruction and cartilage metabolism six-months following reconstruction

BACKGROUND

To determine the association between time from injury to ACL reconstruction (Time^Injury-ACLR) and biochemical markers of cartilage metabolism and inflammation six months following ACL reconstruction (ACLR).

METHODS

Individuals with a unilateral ACL injury were enrolled at initial presentation in the orthopedic clinic; blood was collected six months following ACLR. Enzyme-linked immunosorbent assays were used to analyze the ratio of serum concentrations of type-II collagen breakdown (C2C) to synthesis (CPII), plasma matrix metalloproteinase-3 (MMP-3), interleukin-6 (IL-6), and serum aggrecan neoepitope (ARGS). We used separate linear regressions to assess associations between biochemical markers and Time^Injury-ACLR.

RESULTS

Twenty-two participants (50% females, mean [SD], age 21.9 [4.5] years old; BMI 23.8 [2.6] kg/m²) completed the study. Time^Injury-ACLR ranged from nine to 67days (31.0 [14.4days]). Greater Time^Injury-ACLR predicted greater serum C2C:CPII ratios six months following ACLR (C2C:CPII=0.15 [0.02], R²=0.213, P=0.030). Males (R²=0.733, P=0.001) but not females (R²=0.030, P=0.609) demonstrated a significant association between greater C2C:CPII and Time^Injury-ACLR at the six-month follow-up exam. Time^Injury-ACLR did not associate with IL-6, MMP-3, or ARGS at six months.

CONCLUSIONS

Greater time between injury and ACL reconstruction was associated with greater serum C2C:CPII six months following ACLR in males but not females, and IL-6, MMP-3, and ARGS levels were not associated with Time^Injury-ACLR in males or females. The time between ACL injury and ACLR may affect collagen metabolism in males and should be further investigated in a larger study along with other patient-relevant outcomes.

Risk Factors and Predictors of Significant Chondral Surface Change From Primary to Revision Anterior Cruciate Ligament Reconstruction: A MOON and MARS Cohort Study

BACKGROUND

Articular cartilage health is an important issue following anterior cruciate ligament (ACL) injury and primary ACL reconstruction. Factors present at the time of primary ACL reconstruction may influence the subsequent progression of articular cartilage damage.

HYPOTHESIS

Larger meniscus resection at primary ACL reconstruction, increased patient age, and increased body mass index (BMI) are associated with increased odds of worsened articular cartilage damage at the time of revision ACL reconstruction.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Subjects who had primary and revision data in the databases of the Multicenter Orthopaedics Outcomes Network (MOON) and Multicenter ACL Revision Study (MARS) were included. Reviewed data included chondral surface status at the time of primary and revision surgery, meniscus status at the time of primary reconstruction, primary reconstruction graft type, time from primary to revision ACL surgery, as well as demographics and Marx activity score at the time of revision. Significant progression of articular cartilage damage was defined in each compartment according to progression on the modified Outerbridge scale (increase ≥1 grade) or >25% enlargement in any area of damage. Logistic regression identified predictors of significant chondral surface change in each compartment from primary to revision surgery.

RESULTS

A total of 134 patients were included, with a median age of 19.5 years at revision surgery. Progression of articular cartilage damage was noted in 34 patients (25.4%) in the lateral compartment, 32 (23.9%) in the medial compartment, and 31 (23.1%) in the patellofemoral compartment. For the lateral compartment, patients who had >33% of the lateral meniscus excised at primary reconstruction had 16.9-times greater odds of progression of articular cartilage injury than those with an intact lateral meniscus ( P < .001). For the medial compartment, patients who had <33% of the medial meniscus excised at the time of the primary reconstruction had 4.8-times greater odds of progression of articular cartilage injury than those with an intact medial meniscus ( P = .02). Odds of significant chondral surface change increased by 5% in the lateral compartment and 6% in the medial compartment for each increased year of age ( P ≤ .02). For the patellofemoral compartment, the use of allograft in primary reconstruction was associated with a 15-fold increased odds of progression of articular cartilage damage relative to a patellar tendon autograft ( P < .001). Each 1-unit increase in BMI at the time of revision surgery was associated with a 10% increase in the odds of progression of articular cartilage damage ( P = .046) in the patellofemoral compartment.

CONCLUSION

Excision of the medial and lateral meniscus at primary ACL reconstruction increases the odds of articular cartilage damage in the corresponding compartment at the time of revision ACL reconstruction. Increased age is a risk factor for deterioration of articular cartilage in both tibiofemoral compartments, while increased BMI and the use of allograft for primary ACL reconstruction are associated with an increased risk of progression in the patellofemoral compartment.

Surgical Predictors of Clinical Outcomes After Revision Anterior Cruciate Ligament Reconstruction

BACKGROUND

Revision anterior cruciate ligament (ACL) reconstruction has been documented to have worse outcomes compared with primary ACL reconstruction.

HYPOTHESIS

Certain factors under the control of the surgeon at the time of revision surgery can both negatively and positively affect outcomes.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Patients undergoing revision ACL reconstruction were identified and prospectively enrolled between 2006 and 2011. Data collected included baseline demographics, intraoperative surgical technique and joint disorders, and a series of validated patient-reported outcome instruments (International Knee Documentation Committee [IKDC] subjective form, Knee Injury and Osteoarthritis Outcome Score [KOOS], Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC], and Marx activity rating scale) completed before surgery. Patients were followed up for 2 years and asked to complete an identical set of outcome instruments. Regression analysis was used to control for age, sex, body mass index (BMI), activity level, baseline outcome scores, revision number, time since last ACL reconstruction, and a variety of previous and current surgical variables to assess the surgical risk factors for clinical outcomes 2 years after revision ACL reconstruction.

RESULTS

A total of 1205 patients (697 male [58%]) met the inclusion criteria and were successfully enrolled. The median age was 26 years, and the median time since their last ACL reconstruction was 3.4 years. Two-year follow-up was obtained on 82% (989/1205). Both previous and current surgical factors were found to be significant contributors toward poorer clinical outcomes at 2 years. Having undergone previous arthrotomy (nonarthroscopic open approach) for ACL reconstruction compared with the 1-incision technique resulted in significantly poorer outcomes for the 2-year IKDC ( P = .037; odds ratio [OR], 2.43; 95% CI, 1.05-5.88) and KOOS pain, sports/recreation, and quality of life (QOL) subscales ( P ≤ .05; OR range, 2.38-4.35; 95% CI, 1.03-10.00). The use of a metal interference screw for current femoral fixation resulted in significantly better outcomes for the 2-year KOOS symptoms, pain, and QOL subscales ( P ≤ .05; OR range, 1.70-1.96; 95% CI, 1.00-3.33) as well as WOMAC stiffness subscale ( P = .041; OR, 1.75; 95% CI, 1.02-3.03). Not performing notchplasty at revision significantly improved 2-year outcomes for the IKDC ( P = .013; OR, 1.47; 95% CI, 1.08-1.99), KOOS activities of daily living (ADL) and QOL subscales ( P ≤ .04; OR range, 1.40-1.41; 95% CI, 1.03-1.93), and WOMAC stiffness and ADL subscales ( P ≤ .04; OR range, 1.41-1.49; 95% CI, 1.03-2.05). Factors before revision ACL reconstruction that increased the risk of poorer clinical outcomes at 2 years included lower baseline outcome scores, a lower Marx activity score at the time of revision, a higher BMI, female sex, and a shorter time since the patient's last ACL reconstruction. Prior femoral fixation, prior femoral tunnel aperture position, and knee flexion angle at the time of revision graft fixation were not found to affect 2-year outcomes in this revision cohort.

CONCLUSION

There are certain surgical variables that the physician can control at the time of revision ACL reconstruction that can modify clinical outcomes at 2 years. Whenever possible, opting for an anteromedial portal or transtibial surgical exposure, choosing a metal interference screw for femoral fixation, and not performing notchplasty are associated with significantly better 2-year clinical outcomes.

Subsequent Surgery After Revision Anterior Cruciate Ligament Reconstruction: Rates and Risk Factors From a Multicenter Cohort

BACKGROUND

While revision anterior cruciate ligament reconstruction (ACLR) can be performed to restore knee stability and improve patient activity levels, outcomes after this surgery are reported to be inferior to those after primary ACLR. Further reoperations after revision ACLR can have an even more profound effect on patient satisfaction and outcomes. However, there is a current lack of information regarding the rate and risk factors for subsequent surgery after revision ACLR.

PURPOSE

To report the rate of reoperations, procedures performed, and risk factors for a reoperation 2 years after revision ACLR.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

A total of 1205 patients who underwent revision ACLR were enrolled in the Multicenter ACL Revision Study (MARS) between 2006 and 2011, composing the prospective cohort. Two-year questionnaire follow-up was obtained for 989 patients (82%), while telephone follow-up was obtained for 1112 patients (92%). If a patient reported having undergone subsequent surgery, operative reports detailing the subsequent procedure(s) were obtained and categorized. Multivariate regression analysis was performed to determine independent risk factors for a reoperation.

RESULTS

Of the 1112 patients included in the analysis, 122 patients (11%) underwent a total of 172 subsequent procedures on the ipsilateral knee at 2-year follow-up. Of the reoperations, 27% were meniscal procedures (69% meniscectomy, 26% repair), 19% were subsequent revision ACLR, 17% were cartilage procedures (61% chondroplasty, 17% microfracture, 13% mosaicplasty), 11% were hardware removal, and 9% were procedures for arthrofibrosis. Multivariate analysis revealed that patients aged <20 years had twice the odds of patients aged 20 to 29 years to undergo a reoperation. The use of an allograft at the time of revision ACLR (odds ratio [OR], 1.79; P = .007) was a significant predictor for reoperations at 2 years, while staged revision (bone grafting of tunnels before revision ACLR) (OR, 1.93; P = .052) did not reach significance. Patients with grade 4 cartilage damage seen during revision ACLR were 78% less likely to undergo subsequent operations within 2 years. Sex, body mass index, smoking history, Marx activity score, technique for femoral tunnel placement, and meniscal tearing or meniscal treatment at the time of revision ACLR showed no significant effect on the reoperation rate.

CONCLUSION

There was a significant reoperation rate after revision ACLR at 2 years (11%), with meniscal procedures most commonly involved. Independent risk factors for subsequent surgery on the ipsilateral knee included age <20 years and the use of allograft tissue at the time of revision ACLR.

Initial medical management of rotator cuff tears: a demographic analysis of surgical and nonsurgical treatment in the United States Medicare population

BACKGROUND

Rotator cuff tears have a lifetime incidence between 25% and 40% in the United States, but optimum treatment strategies and protocol have not yet been widely accepted. This study evaluated the proportions of patients treated with nonoperative and operative modalities and how this proportion has changed during an 8-year period (2005-2012) among patients with Medicare.

METHODS

Using the PearlDiver patient record database, we identified Medicare patients having been diagnosed with a rotator cuff tear. These patients were then stratified on the basis of treatment with physical therapy, subacromial/glenohumeral injection, or rotator cuff repair. We analyzed the data in regard to standard demographic information, comorbidities, and the Charlson Comorbidity Index.

RESULTS

During the study period, 878,049 patients were identified and 397,116 patients had rotator cuff repair. The proportion of patients treated initially with physical therapy dropped from 30.0% in 2005 to 13.2% in 2012, and the subacromial/glenohumeral injection proportion decreased from 6.00% to 4.19% (P < .001). The proportion of patients who had rotator cuff repair increased from 33.8% to 40.4% from 2005 to 2012 (P < .001). Charlson Comorbidity Indexes were significantly lower in operative patients compared with each nonoperative treatment examined.

DISCUSSION

This analysis demonstrates a significant decrease in the initial trial of nonoperative treatment and an increase in the rate of surgery. Patients undergoing rotator cuff repair had fewer comorbidities than those undergoing nonoperative treatments. It also demonstrates that patients who had a trial of injection had a higher incidence of eventual rotator cuff repair compared with the patients with an initial trial of physical therapy.

Effect of graft choice on the outcome of revision anterior cruciate ligament reconstruction in the Multicenter ACL Revision Study (MARS) Cohort

BACKGROUND

Most surgeons believe that graft choice for anterior cruciate ligament (ACL) reconstruction is an important factor related to outcome; however, graft choice for revision may be limited due to previously used grafts.

HYPOTHESES

Autograft use would result in increased sports function, increased activity level, and decreased osteoarthritis symptoms (as measured by validated patient-reported outcome instruments). Autograft use would result in decreased graft failure and reoperation rate 2 years after revision ACL reconstruction.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Patients undergoing revision ACL reconstruction were identified and prospectively enrolled by 83 surgeons at 52 sites. Data collected included baseline demographics, surgical technique, pathologic abnormalities, and the results of a series of validated, patient-reported outcome instruments (International Knee Documentation Committee [IKDC], Knee injury and Osteoarthritis Outcome Score [KOOS], Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC], and Marx activity rating score). Patients were followed up at 2 years and asked to complete the identical set of outcome instruments. Incidences of additional surgery and reoperation due to graft failure were also recorded. Multivariate regression models were used to determine the predictors (risk factors) of IKDC, KOOS, WOMAC, Marx scores, graft rerupture, and reoperation rate at 2 years after revision surgery.

RESULTS

A total of 1205 patients (697 [58%] males) were enrolled. The median age was 26 years. In 88% of patients, this was their first revision, and 341 patients (28%) were undergoing revision by the surgeon who had performed the previous reconstruction. The median time since last ACL reconstruction was 3.4 years. Revision using an autograft was performed in 583 patients (48%), allograft was used in 590 (49%), and both types were used in 32 (3%). Questionnaire follow-up was obtained for 989 subjects (82%), while telephone follow-up was obtained for 1112 (92%). The IKDC, KOOS, and WOMAC scores (with the exception of the WOMAC stiffness subscale) all significantly improved at 2-year follow-up (P < .001). In contrast, the 2-year Marx activity score demonstrated a significant decrease from the initial score at enrollment (P < .001). Graft choice proved to be a significant predictor of 2-year IKDC scores (P = .017). Specifically, the use of an autograft for revision reconstruction predicted improved score on the IKDC (P = .045; odds ratio [OR] = 1.31; 95% CI, 1.01-1.70). The use of an autograft predicted an improved score on the KOOS sports and recreation subscale (P = .037; OR = 1.33; 95% CI, 1.02-1.73). Use of an autograft also predicted improved scores on the KOOS quality of life subscale (P = .031; OR = 1.33; 95% CI, 1.03-1.73). For the KOOS symptoms and KOOS activities of daily living subscales, graft choice did not predict outcome score. Graft choice was a significant predictor of 2-year Marx activity level scores (P = .012). Graft rerupture was reported in 37 of 1112 patients (3.3%) by their 2-year follow-up: 24 allografts, 12 autografts, and 1 allograft and autograft. Use of an autograft for revision resulted in patients being 2.78 times less likely to sustain a subsequent graft rupture compared with allograft (P = .047; 95% CI, 1.01-7.69).

CONCLUSION

Improved sports function and patient-reported outcome measures are obtained when an autograft is used. Additionally, use of an autograft shows a decreased risk in graft rerupture at 2-year follow-up. No differences were noted in rerupture or patient-reported outcomes between soft tissue and bone-patellar tendon-bone grafts. Surgeon education regarding the findings of this study has the potential to improve the results of revision ACL reconstruction.

Surgical Trends in the Treatment of Superior Labrum Anterior and Posterior Lesions of the Shoulder: Analysis of Data From the American Board of Orthopaedic Surgery Certification Examination Database

BACKGROUND

After failure of nonoperative treatment, repair has long been the primary treatment option for symptomatic superior labrum anterior and posterior (SLAP) lesions of the shoulder. There is growing evidence to support both biceps tenotomy and tenodesis as effective alternative treatments for SLAP lesions.

HYPOTHESES

For patients with isolated SLAP lesions, the frequency of SLAP repair has decreased, while treatment with biceps tenodesis and tenotomy has increased. Similar trends are expected in patients with SLAP lesions undergoing concomitant rotator cuff repair.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A query of the American Board of Orthopaedic Surgery part II database was performed from 2002 to 2011. The database was searched for patients with isolated SLAP lesions undergoing SLAP repair, open biceps tenodesis, arthroscopic biceps tenodesis, or biceps tenotomy. The database was then queried a second time for patients undergoing arthroscopic rotator cuff repair with concomitant SLAP repair, biceps tenodesis, or biceps tenotomy.

RESULTS

From 2002 to 2011, there were 8963 cases reported for the treatment of an isolated SLAP lesion and 1540 cases reported for the treatment of SLAP lesions with concomitant rotator cuff repair. For patients with isolated SLAP lesions, the proportion of SLAP repairs decreased from 69.3% to 44.8% (P < .0001), while biceps tenodesis increased from 1.9% to 18.8% (P < .0001), and biceps tenotomy increased from 0.4% to 1.7% (P = .018). For patients undergoing concomitant rotator cuff repair, SLAP repair decreased from 60.2% to 15.3% (P < .0001), while biceps tenodesis or tenotomy increased from 6.0% to 28.0% (P < .0001). There was a significant difference in the mean age of patients undergoing SLAP repair (37.1 years) versus biceps tenodesis (47.2 years) versus biceps tenotomy (55.7 years) (P < .0001).

CONCLUSION

Practice trends for orthopaedic board candidates indicate that the proportion of SLAP repairs has decreased over time, with an increase in biceps tenodesis and tenotomy. Increased patient age correlates with the likelihood of treatment with biceps tenodesis or tenotomy versus SLAP repair.

Anterior Cruciate Ligament Injury, Return to Play, and Reinjury in the Elite Collegiate Athlete: Analysis of an NCAA Division I Cohort

BACKGROUND

Graft survivorship, reinjury rates, and career length are poorly understood after anterior cruciate ligament (ACL) reconstruction in the elite collegiate athlete. The purpose of this study was to examine the outcomes of ACL reconstruction in a National Collegiate Athletic Association (NCAA) Division I athlete cohort.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A retrospective chart review was performed of all Division I athletes at a single public university from 2000 to 2009 until completion of eligibility. Athletes were separated into 2 cohorts: those who underwent precollegiate ACL reconstruction (PC group) and those who underwent intracollegiate reconstruction (IC group). Graft survivorship, reoperation rates, and career length information were collected.

RESULTS

Thirty-five athletes were identified with precollegiate reconstruction and 54 with intracollegiate reconstruction. The PC group had a 17.1% injury rate with the original graft, with a 20.0% rate of a contralateral ACL injury. For the IC group, the reinjury rates were 1.9% with an ACL graft, with an 11.1% rate of a contralateral ACL injury after intracollegiate ACL reconstruction. The athletes in the PC group used 78% of their total eligibility (average, 3.11 years). The athletes in the IC group used an average of 77% of their remaining NCAA eligibility; 88.3% of those in the IC group played an additional non-redshirt year after their injury. The reoperation rate for the PC group was 51.4% and was 20.4% for the IC group.

CONCLUSION

Reoperation and reinjury rates are high after ACL reconstruction in the Division I athlete. Precollegiate ACL reconstruction is associated with a very high (37.1%) rate of repeat ACL reinjuries to the graft or opposite knee. The majority of athletes are able to return to play after successful reconstruction.

Effects of knee extension constraint training on knee flexion angle and peak impact ground-reaction force

BACKGROUND

Low compliance with training programs is likely to be one of the major reasons for inconsistency of the data regarding the effectiveness of current anterior cruciate ligament (ACL) injury prevention programs. Training methods that reduce training time and cost could favorably influence the effectiveness of ACL injury prevention programs. A newly designed knee extension constraint training device may serve this purpose.

HYPOTHESIS

(1) Knee extension constraint training for 4 weeks would significantly increase the knee flexion angle at the time of peak impact posterior ground-reaction force and decrease peak impact ground-reaction forces during landing of a stop-jump task and a side-cutting task, and (2) the training effects would be retained 4 weeks after completion of the training program.

STUDY DESIGN

Controlled laboratory study.

METHODS

Twenty-four recreational athletes were randomly assigned to group A or B. Participants in group A played sports without wearing a knee extension constraint device for 4 weeks and then played sports while wearing the device for 4 weeks, while participants in group B underwent a reversed protocol. Both groups were tested at the beginning of week 1 and at the ends of weeks 4 and 8 without wearing the device. Knee joint angles were obtained from 3-dimensional videographic data, while ground-reaction forces were measured simultaneously using force plates. Analyses of variance were performed to determine the training effects and the retention of training effects.

RESULTS

Participants in group A significantly increased knee flexion angles and decreased ground-reaction forces at the end of week 8 (P ≤ .012). Participants in group B significantly increased knee flexion angles and decreased ground-reaction forces at the ends of weeks 4 and 8 (P ≤ .007). However, participants in group B decreased knee flexion angles and increased ground-reaction forces at the end of week 8 in comparison with the end of week 4 (P ≤ .009).

CONCLUSION

Knee extension constraint training for 4 weeks significantly altered lower extremity movement patterns and transferred these changes in lower extremity movement patterns to stop-jump and side-cutting tasks in which ACL injuries frequently occur. Training effects were retained 4 weeks after the training was completed but were diminished in magnitude.

CLINICAL RELEVANCE

A knee extension constraint device may be a useful training tool in future ACL injury prevention programs to alter movement patterns without extra training time.

Comparison of fixation methods after anteromedialization osteotomy of the tibial tubercle for patellar instability

PURPOSE

The aim of this study was to evaluate the biomechanical strength of two 4.5-mm screws and three 3.5-mm screws for fixation of the tibial tubercle after anteromedialization osteotomy.

METHODS

Anteromedialization of the tibial tubercle was performed on 5 pairs of fresh-frozen cadaveric lower extremities. One leg from each pair was randomized to fixation with two 4.5-mm screws and the contralateral leg to fixation with three 3.5-mm screws. Each specimen was loaded cyclically to simulate an active straight-leg raise and then to failure while displacement of the tubercle fragment was recorded.

RESULTS

There was no difference in mean tubercle fragment displacement under cyclic loading at any cycle number (P > .352). Maximum failure load for osteotomies secured with two 4.5-mm screws was 1,459 ± 540 N, and for three 3.5-mm screws it was 1,360 ± 707 N. This was not a statistically significant difference (P = .723). Tubercle migration of 7 mm was chosen as clinical failure. At this amount of displacement, mean load was 1,085 ± 398 N and 764 ± 313 N in the 4.5-mm and 3.5-mm groups, respectively, which was also not significantly different (P = .146).

CONCLUSIONS

Both 2 × 4.5-mm and 3 × 3.5-mm screw constructs after tibial tubercle anteromedialization are equally capable of withstanding physiologic forces like those encountered during an active straight-leg raise and have similar failure strength.

CLINICAL RELEVANCE

Although both configurations are comparable, the use of the smaller 3.5-mm screws may reduce the need for hardware removal related to prominence and soft tissue irritation.

Biomechanical analysis of a double-loaded glenoid anchor configuration: can fewer anchors provide equivalent fixation?

BACKGROUND

Bankart repair with multiple anchor holes concentrated in the anterior-inferior glenoid may contribute to glenoid weakening and potentially may induce glenoid failure.

PURPOSE

To compare the biomechanical strength of a Bankart repair construct that used 3 single-loaded suture anchors versus a repair construct that used 2 double-loaded suture anchors.

STUDY DESIGN

Comparative laboratory study.

METHODS

A standard Bankart lesion was created in 18 human cadaveric shoulders (9 matched pairs). Within each matched pair, 1 repair construct used 3 single-loaded anchors, whereas the other used 2 double-loaded suture anchors. Measured outcomes (load, stiffness, and energy absorbed) were recorded at failure and at 2 mm of labral displacement. Constructs were loaded to failure with a materials testing device that had differential variable reluctance transducers for displacement measurements.

RESULTS

The double-loaded anchor construct had a significantly higher ultimate tensile load (944 ± 231 vs 784 ± 287 N; P = .03). For the other measures (load at 2 mm of displacement, energy absorbed at failure and at 2 mm of displacement and stiffness), there were no significant differences between tested constructs.

CONCLUSION

A Bankart repair construct that used 2 double-loaded anchors was either superior to or equal to a repair construct that used 3 single-loaded anchors in all measured outcomes.

CLINICAL RELEVANCE

Using 2 double-loaded suture anchors for a Bankart repair may limit anchor holes in the glenoid and reduce the risk of postsurgical glenoid fracture while providing a stable repair construct.

Humeral retrotorsion in collegiate baseball pitchers with throwing-related upper extremity injury history

Background:

Collegiate baseball pitchers, as well as position players, exhibit increased humeral retrotorsion compared with individuals with no history of overhead sport participation. Whether the humeral retrotorsion plays a role in the development of throwing-related injuries that are prevalent in collegiate baseball pitchers is unknown.

Hypotheses:

Humeral retrotorsion will be significantly different in collegiate pitchers with throwing-related shoulder or elbow injury history compared with pitchers with no injury history. Humeral retrotorsion can also discriminate participants with and without shoulder or elbow injury.

Study Design:

Cross-sectional study.

Methods:

Comparisons of ultrasonographically-obtained humeral retrotorsion were made between 40 collegiate pitchers with and without history of throwing-related shoulder or elbow injury. The ability of humeral retrotorsion to discriminate injury history was determined from the receiver operating characteristic area under the curve.

Results:

Participants with an elbow injury history demonstrated a greater humeral retrotorsion limb difference (mean difference = 7.2°, P = 0.027) than participants with no history of upper extremity injury. Participants with shoulder injury history showed no differences in humeral torsion compared with participants with no history of injury. Humeral retrotorsion limb difference exhibited a fair ability (receiver operating characteristic area under the curve = 0.74) to discriminate elbow injury history.

Conclusions:

Collegiate pitchers with a history of elbow injury exhibited a greater limb difference in humeral retrotorsion compared with pitchers with no history of injury. No differences in humeral retrotorsion variables were present in participants with and without shoulder injury history.

Clinical Relevance:

Baseball players with a history of elbow injury demonstrated increased humeral retrotorsion, suggesting that the amount of retrotorsion and the development of elbow injury may be associated.

Humeral component revision arthroplasty: outcomes of a split osteotomy technique

BACKGROUND

The purpose of our study was to report results on 13 patients who underwent shoulder revision surgery of a well-fixed cemented humeral component assisted by a longitudinal split osteotomy. Limited data have been published on humeral stem revision using an osteotomy to facilitate removal of a well-fixed humeral component.

MATERIALS AND METHODS

Between July 1996 and July 2004, 13 humeral component revisions of well-fixed cemented stems were performed for pain and functional limitation. The patients' preoperative and postoperative function and outcome were evaluated by physical examination, visual analog scale (VAS) for pain, Simple Shoulder Test (SST), American Shoulder and Elbow Surgeons (ASES) score, Short Form-12 (SF-12), and radiographic assessment.

RESULTS

At a mean follow-up of 30 months, from preoperatively to postoperatively, the VAS pain score improved from 7.8 to 2.3 (P = .012), the ASES score improved from 19.6 to 58.9 (P < .011), the SST score improved from 1.4 to 4.6 (P < .011), and significant changes were demonstrated on the mental component of the SF-12, with improvement from 49.8 to 59.4 (P < .025). Analysis of range of motion from preoperatively to postoperatively revealed that the mean external rotation improved from 24.4° to 40° (P < .042), and mean forward elevation improved from 60.6° to 89.4°, although this change was not significant (P = .067). There were no iatrogenic fractures. Radiographic follow-up demonstrated no evidence of humeral loosening or nonunion.

CONCLUSIONS

A longitudinal humeral split osteotomy is a safe and effective technique for revision of a well-fixed humeral stem.

Effects of a knee extension constraint brace on lower extremity movements after ACL reconstruction

BACKGROUND

Patients have high reinjury rates after ACL reconstruction. Small knee flexion angles and large peak posterior ground reaction forces in landing tasks increase ACL loading.

QUESTIONS/PURPOSES

We determined the effects of a knee extension constraint brace on knee flexion angle, peak posterior ground reaction force, and movement speed in functional activities of patients after ACL reconstruction.

PATIENTS AND METHODS

Six male and six female patients 3.5 to 6.5 months after ACL reconstruction participated in the study. Three-dimensional videographic and force plate data were collected while patients performed level walking, jogging, and stair descent wearing a knee extension constraint brace, wearing a nonconstraint brace, and not wearing a knee brace. Knee flexion angle at initial foot contact with the ground, peak posterior ground reaction force, and movement speed were compared across brace conditions and between genders.

RESULTS

Wearing the knee extension constraint brace increased the knee flexion angle at initial foot contact for each activity when compared with the other two brace conditions. Wearing the knee extension constraint brace also decreased peak posterior ground reaction force during walking but not during jogging and stair descent.

CONCLUSIONS

Although the knee extension constraint brace did not consistently reduce the peak posterior ground reaction force in all functional activities, it consistently increased knee flexion angle and should reduce ACL loading as suggested by previous studies. These results suggest the knee extension constraint brace has potential as a rehabilitation tool to alter lower extremity movement patterns of patients after ACL reconstruction to address high reinjury rates.

Repair of lesser tuberosity osteotomy for shoulder arthroplasty: biomechanical evaluation of the Backpack and Dual Row techniques

BACKGROUND

Subscapularis dysfunction following total shoulder arthroplasty can result in permanent loss of function. The lesser tuberosity osteotomy (LTO) has been proposed as a method which utilizes bone-to-bone healing to improve subscapularis function. This study evaluates the biomechanical properties of two described techniques for LTO repair. We hypothesized that a Dual Row repair would be stronger and demonstrate less cyclic displacement than a Backpack repair.

MATERIALS AND METHODS

Ten matched pairs of cadaveric humeri were dissected, leaving the subscapularis intact, and a lesser tuberosity osteotomy was performed. Matched shoulders were randomized to either a Backpack repair or a Dual Row repair. Repairs were subjected to cyclic loading to 180 N for 500 cycles, followed by ramp-up loading to ultimate failure. Clinical failure was defined as displacement >5 mm after 500 cycles.

RESULTS

Displacement after 500 cycles was significantly greater for the Backpack repair (6.9 mm) than for the Dual Row repair (4.6 mm) (P = .007). Most displacement occurred on the first cycle (Backpack, 4.6 mm; Dual Row, 2.1 mm) (P < .001). There was a trend toward a higher clinical failure rate for the Backpack repair (8/10) than the Dual Row repair (3/10). Ultimate tensile strength was significantly greater for the Dual Row repair (632.3 N) than for the Backpack repair (510.9 N) (P = .01).

CONCLUSION

The Dual Row technique is significantly stronger and demonstrates less cyclic displacement than the Backpack technique. Clinical studies are needed to determine the impact of LTO repair technique on subscapularis function following shoulder arthroplasty.

Concentric and eccentric torque of the hip musculature in individuals with and without patellofemoral pain

CONTEXT

Individuals suffering from patellofemoral pain have previously been reported to have decreased isometric strength of the hip musculature; however, no researchers have investigated concentric and eccentric torque of the hip musculature in individuals with patellofemoral pain.

OBJECTIVE

To compare concentric and eccentric torque of the hip musculature in individuals with and without patellofemoral pain.

DESIGN

Case control.

SETTING

Research laboratory.

PATIENTS OR OTHER PARTICIPANTS

Twenty participants with patellofemoral pain (age = 26.8 +/- 4.5 years, height = 171.8 +/- 8.4 cm, mass = 72.4 +/- 16.8 kg) and 20 control participants (age = 25.6 +/- 2.8 years, height = 169.5 +/- 8.9 cm, mass = 70.0 +/- 16.9 kg) were tested. Volunteers with patellofemoral pain met the following criteria: knee pain greater than or equal to 3 cm on a 10-cm visual analog scale, insidious onset of symptoms not related to trauma, pain with palpation of the patellar facets, and knee pain during 2 of the following activities: stair climbing, jumping or running, squatting, kneeling, or prolonged sitting. Control participants were excluded if they had a prior history of patellofemoral pain, knee surgery in the past 2 years, or current lower extremity injury that limited participation in physical activity.

INTERVENTION(S)

Concentric and eccentric torque of the hip musculature was measured on an isokinetic dynamometer. All volunteers performed 5 repetitions of each strength test. Separate multivariate analyses of variance were performed to compare concentric and eccentric torque of the hip extensors, abductors, and external rotators between groups.

MAIN OUTCOME MEASURE(S)

Average and peak concentric and eccentric torque of the hip extensors, abductors, and external rotators. Torque measures were normalized to the participant's body weight multiplied by height.

RESULTS

The patellofemoral pain group was weaker than the control group for peak eccentric hip abduction torque (F(1,38) = 6.630, P = .014), and average concentric (F(1,38) = 4.156, P = .048) and eccentric (F(1,38) = 4.963, P = .032) hip external rotation torque.

CONCLUSIONS

The patellofemoral pain group displayed weakness in eccentric hip abduction and hip external rotation, which may allow for increased hip adduction and internal rotation during functional movements.

Bony instability of the shoulder

Instability of the shoulder is a common problem treated by many orthopaedists. Instability can result from baseline intrinsic ligamentous laxity or a traumatic event-often a dislocation that injures the stabilizing structures of the glenohumeral joint. Many cases involve soft-tissue injury only and can be treated successfully with repair of the labrum and ligamentous tissues. Both open and arthroscopic approaches have been well described, with recent studies of arthroscopic soft-tissue techniques reporting results equal to those of the more traditional open techniques. Over the last decade, attention has focused on the concept of instability of the shoulder mediated by bony pathology such as a large bony Bankart lesion or an engaging Hill-Sachs lesion. Recent literature has identified unrecognized large bony lesions as a primary cause of failure of arthroscopic reconstruction for instability, a major cause of recurrent instability, and a difficult diagnosis to make. Thus, although such bony lesions may be relatively rare compared with soft-tissue pathology, they constitute a critically important entity in the management of shoulder instability. Smaller bony lesions may be amenable to arthroscopic treatment, but larger lesions often require open surgery to prevent recurrent instability. This article reviews recent developments in the diagnosis and treatment of bony instability.

Effect of NKISK on tendon lengthening: an in vivo model for various clinically applicable dosing regimens

One proposed mechanism of tendon lengthening is the "sliding fibril" hypothesis, in which tendons lengthen through the sliding of discontinuous fibrils after release of decorin-fibronectin interfibrillar bonds. The pentapeptide NKISK has been reported to inhibit the binding of decorin, a proteoglycan on the surface of collagen fibrils, to fibronectin, a tissue adhesion molecule, which are thought to play a role in interfibrillar binding. Prior investigations have demonstrated that NKISK produces in vivo tendon lengthening. This study investigates the effect of potential clinically applicable NKISK injection regimens in an in vivo model. One hundred and thirteen male Sprague-Dawley rats were divided into 15 different treatment groups, each receiving percutaneous patellar tendon injections of NKISK, QKTSK (a "nonsense" pentapeptide), or PBS of varying volumes, concentrations, and injection schedules. Following sacrifice, the patellar tendon lengths were measured in all groups, and biomechanical testing was performed with comparisons made to the contralateral, untreated control limbs. Tendon lengthening was significantly greater (p < or = 0.05) in nearly all NKISK-treated tendons as compared to PBS- and QKTSK-treated tendons and was dose-dependent. Measured lengthening was less in rats whose sacrifice was delayed following the final injection of NKISK, which likely indicates recontraction of lengthened tendons, but they remained significantly longer than the controls. Biomechanical testing did not reveal significant differences in ultimate load, modulus, stiffness, or displacement. This study demonstrates that NKISK given in clinically plausible dosing regimens produces dose-dependent tendon lengthening in an in vivo setting with minimal effects on the mechanical properties of the treated tendons.

Repair of patellar tendon rupture using suture anchors

Acute isolated rupture of the patellar tendon traditionally has been repaired via transpatellar suture tunnels. This retrospective study evaluated the demographics and epidemiology of this injury as well as the effectiveness and complication rates of our suture anchor technique. Between 1993 and 2005, a total of 82 cases of patellar tendon disruption in 71 patients were repaired. Fourteen cases involved basic primary repair with suture anchors of an acute isolated rupture of the patellar tendon and had an average follow-up of 29 months (range: 3-112 months). There were 3 (21%) failures of repair. The remaining 11 patients had excellent range of motion and strength and returned to their preoperative level of function. These results are comparable with other reports in the literature. The suture anchor technique thus represents a viable option for repair of patellar tendon ruptures and should be investigated further with a randomized, controlled trial.

Revision arthroscopic shoulder instability repair

PURPOSE

The purpose of this study was to report on a difficult patient population and to critically evaluate the role of revision arthroscopic stabilization surgery.

METHODS

Eighteen patients with failed traumatic instability repairs were treated with revision arthroscopic labral fixation and plication with a mean follow-up of 29.7 months (range, 24 to 48 months). There were 15 male patients and 3 female patients with a mean age of 28.6 years (range, 15 to 50 years). Of the 18 patients, 9 were Workers' Compensation cases. The 18 patients had a mean of 1.55 surgeries before our revision surgery, with 9 having a component of thermocapsular shrinkage. The patients' characteristics, operative techniques, and findings were recorded, and their clinical outcome was critically evaluated (via physical examination, visual analog pain scale, Simple Shoulder Test, American Shoulder and Elbow Surgeons score, and Short Form 12).

RESULTS

The revision surgery incorporated a 4-portal technique via a mean of 4.6 suture anchors and 3 plication stitches, and 15 patients received a rotator interval closure. At the follow-up evaluation, 13 patients had satisfactory results whereas 5 cases were considered clinical failures (with recurrent instability in 3 and pain in 2). There was clinically significant improvement in pain score (6 preoperatively v 2 postoperatively, P = .0001), Simple Shoulder Test score (6 preoperatively v 10 postoperatively, P = .001), and American Shoulder and Elbow Surgeons score (50 preoperatively v 76 postoperatively, P = .001). Of the 9 Workers' Compensation patients, 5 were able to return to their original work.

CONCLUSIONS

Arthroscopic revision instability repair by use of a combination of suture anchors, plication stitches, and rotator interval closure can result in a satisfactory outcome in selected patients.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

The use of suture anchors to repair the ruptured quadriceps tendon

Quadriceps tendon rupture is an incapacitating injury that usually requires surgical repair. Traditional repair methods involve transpatellar suture tunnels, but recent reports have introduced the idea of using suture anchors to repair the ruptured tendon. We present 5 cases of our technique of using suture anchors to repair the ruptured quadriceps tendon.

Kinematics and electromyography of landing preparation in vertical stop-jump: risks for noncontact anterior cruciate ligament injury

BACKGROUND

Biomechanical analysis of stop-jump tasks has demonstrated gender differences during landing and a potential increase in risk of noncontact anterior cruciate ligament injury for female athletes. Analysis of landing preparation could advance our understanding of neuromuscular control in movement patterns and be applied to the development of prevention strategies for noncontact anterior cruciate ligament injury.

HYPOTHESIS

There are differences in the lower extremity joint angles and electromyography of male and female recreational athletes during the landing preparation of a stop-jump task.

STUDY DESIGN

Controlled laboratory study.

METHODS

Three-dimensional videographic and electromyographic data were collected for 36 recreational athletes (17 men and 19 women) performing vertical stop-jump tasks. Knee and hip angular motion patterns were determined during the flight phase before landing.

RESULTS

Knee and hip motion patterns and quadriceps and hamstring activation patterns exhibited significant gender differences. Female subjects generally exhibited decreased knee flexion (P = .001), hip flexion (P = .001), hip abduction (P = .001), and hip external rotation (P = .03); increased knee internal rotation (P = .001); and increased quadriceps activation (P = .001) compared with male subjects. Female subjects also exhibited increased hamstring activation before landing but a trend of decreased hamstring activation after landing compared with male subjects (P = .001).

CONCLUSION

Lower extremity motion patterns during landing of the stop-jump task are preprogrammed before landing. Female subjects prepared for landing with decreased hip and knee flexion at landing, increased quadriceps activation, and decreased hamstring activation, which may result in increased anterior cruciate ligament loading during the landing of the stop-jump task and the risk for noncontact ACL injury.

Effect of lateral meniscus allograft on shoulder articular contact areas and pressures

The objective of this study was to determine the effect of a lateral meniscus allograft on the articular contact area and pressures across the glenohumeral joint under compressive loads of 220 N and 440 N. Eight fresh-frozen shoulders were used, and contact areas and pressures were determined with a Tekscan flexible tactile force sensor. Testing conditions included a normal glenohumeral joint and one interposed with a lateral meniscus allograft. Using the Tekscan sensing equipment, we evaluated the total force (in Newtons), contact area (in square millimeters), mean contact pressure (in kilograms per square centimeter), peak force (in Newtons), and peak contact pressure (in kilograms per square centimeter). The interposed lateral meniscus allograft group showed a statistically significant decrease in total force at both 220 N and 440 N, as well as a decrease in contact area for the 220-N testing condition. There were no statistically significant differences between the two groups in contact area at 440 N or in peak forces or peak contact areas for either 220-N or 440-N testing condition. Biomechanically biologic resurfacing with a lateral meniscus allograft of the glenohumeral joint is supported by decreased forces on the glenoid surface.

Evaluation of the medial elbow in the throwing athlete

The valgus forces generated by throwing athletes can cause injuries and permanently damage the medial elbow structures. Clinicians must have a clear understanding of the ulnar collateral ligament complex and the associated medial elbow structures at risk in these athletes. Taking a detailed history, conducting a physical examination, and obtaining imaging studies will aid in making the correct diagnosis and giving these injuries the appropriate treatment. Pain around the medial elbow is of concern to throwing athletes, coaches, and medical staff. Valgus forces generated by the throwing motion add considerable stress to the medial elbow structures and thus potentially cause injury. Baseball players, particularly pitchers, are most often affected, but athletes participating in sports such as football, volleyball, water polo, tennis, and javelin throwing can also be affected.

Decision making in contemporary shoulder arthroplasty

Clinical experience with humeral implants has evolved over the past decade, along with a better understanding of shoulder anatomy and function. There is no question that surgeons are getting better at restoring normal anatomic relationships than in preceding decades. Whether or not this impacts implant longevity will only be known with time and further follow-up. Even over the short term, it is difficult to ascertain whether new prosthetic designs have improved patient function as well as has been implied by the related biomechanical studies. Most surgeons with experience using old and new systems realize a greater sense of predictability in achieving their surgical goals when using more modern implants. Concerns over the durability of prosthetic systems with multiple moving parts and hand-tightened locking mechanisms have almost been forgotten in shoulder arthroplasty, but time will also reveal their importance. New glenoid designs have been less exciting, the major problem being one of developing appropriate materials. Polyethylene does not behave like normal cartilage, and its wear is constant and unforgiving. Surgeons now better understand how to reconstruct the normal glenoid position and achieve more secure early fixation than in the past, but this does not promise long-term durability and freedom from complications.

Thermal microdebridement does not affect the time zero biomechanical properties of human patellar tendons

BACKGROUND

Thermal microdebridement for the treatment of chronic tendinopathy has recently been introduced. The effect of thermal microdebridement on the biomechanical properties of human tendons, however, remains unknown.

HYPOTHESIS

Thermal microdebridement does not affect the biomechanical properties of human patellar tendons in a cadaveric model at the time of initial treatment.

STUDY DESIGN

Controlled laboratory study.

METHODS

The central 15 mm of 12 matched, human (mean age, 71 years; 8 male, 4 female), fresh-frozen patellar tendons was divided into 3 equal 5-mm specimens. The treatment group (n = 12) underwent thermal microdebridement with a radiofrequency probe. A sham treatment group (n = 12) underwent insertion of a deactivated probe. The control group (n = 12) underwent no treatment. After treatment, each specimen was tested to failure in a servo-hydraulic materials testing machine at an elongation rate of 3 mm/s. One-way repeated measures analysis of variance was used to determine differences between groups.

RESULTS

No significant difference in ultimate stress at failure, elastic modulus, strain energy density, or strain at maximum load was found between the groups. The ultimate stress at failure for the treatment, sham, and control groups was 61.0, 66.7, and 63.0 MPa, respectively (P = .653), and the strain at maximum load was 0.12, 0.11, and 0.09, respectively (P = .279).

CONCLUSIONS

Thermal microdebridement does not affect the biomechanical properties of cadaveric human patellar tendons at the time of initial treatment.

CLINICAL RELEVANCE

It may be safe to proceed with aggressive rehabilitation after thermal microdebridement of the patellar tendon. However, the results in this cadaveric model should be interpreted with caution. Additional studies using an in vivo model will be required to completely assess the effects of thermal microdebridement on the biomechanical properties of human patellar tendons.

Glenohumeral volume reduction in arthroscopic shoulder reconstruction: a cadaveric analysis of suture plication and thermal capsulorrhaphy

PURPOSE

The purpose of this study was to objectively assess glenohumeral volume changes after arthroscopic suture plication, arthroscopic thermal capsulorrhaphy, and combined suture and thermal treatment.

TYPE OF STUDY

Cadaveric study.

METHODS

Five matched pairs of cadaver shoulders were treated with either thermal capsulorrhaphy (n = 5) or arthroscopic suture plication (n = 5). The shoulders treated with plication were then treated with thermal capsulorrhaphy to form a combined treatment group (plication and thermal). Preoperative and postoperative glenohumeral volume measurements were obtained, and the techniques were statistically compared with a 1-factor analysis of variance.

RESULTS

All 3 procedures produced marked decreases in glenohumeral capsular volume. Suture plication reduced intra-articular volume an average of 19.0%. Thermal capsulorrhaphy resulted in a mean capsular volume reduction of 33.4%. Combined treatment with suture plication and thermal capsulorrhaphy reduced glenohumeral volume an average of 41.0%. Both thermal capsulorrhaphy and the combined treatment produced significantly greater reduction in glenohumeral volume than plication alone (P <.0001). Although combined suture plication and thermal capsulorrhaphy resulted in greater reduction in capsular volume than thermal capsulorrhaphy alone, the differences were not statistically significant.

CONCLUSIONS

Our results indicate that arthroscopic suture plication and thermal capsulorrhaphy are both effective in reducing glenohumeral intra-articular volume. Thermal capsulorrhaphy alone or in combination with suture plication led to significantly greater reduction in capsular volume when compared with isolated suture plication.