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.

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.

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.

Rate of infection following revision anterior cruciate ligament reconstruction and associated patient- and surgeon-dependent risk factors: Retrospective results from MOON and MARS data collected from 2002 to 2011

Infection is a rare occurrence after revision anterior cruciate ligament reconstruction (rACLR). Because of the low rates of infection, it has been difficult to identify risk factors for infection in this patient population. The purpose of this study was to report the rate of infection following rACLR and assess whether infection is associated with patient- and surgeon-dependent risk factors. We reviewed two large prospective cohorts to identify patients with postoperative infections following rACLR. Age, sex, body mass index (BMI), smoking status, history of diabetes, and graft choice were recorded for each patient. The association of these factors with postoperative infection following rACLR was assessed. There were 1423 rACLR cases in the combined cohort, with 9 (0.6%) reporting postoperative infections. Allografts had a higher risk of infection than autografts (odds ratio, 6.8; 95% CI, 0.9-54.5; p = .045). Diabetes (odds ratio, 28.6; 95% CI, 5.5-149.9; p = .004) was a risk factor for infection. Patient age, sex, BMI, and smoking status were not associated with risk of infection after rACLR.

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.

Association Between Bone Marrow Lesions, Chondral Lesions, and Pain in Patients Without Radiographic Evidence of Degenerative Joint Disease Who Underwent Arthroscopic Partial Meniscectomy

Background

Bone marrow lesions (BMLs) have been found on magnetic resonance imaging in patients with meniscal tears.

Purpose

We sought to determine the prevalence and location of BMLs, the association between BMLs and chondral lesions, and the association between BMLs and pain in patients without radiographic evidence of degenerative joint disease who underwent arthroscopic partial meniscectomy (APM).

Study Design

Cohort study; Level of evidence, 2.

Methods

We performed a secondary analysis of the Chondral Lesions And Meniscus Procedures (ChAMP) randomized controlled trial. BMLs were assessed on preoperative magnetic resonance imaging, and chondral lesions were documented at the time of surgery. Pain was assessed preoperatively and at 1 year after APM using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the Knee injury and Osteoarthritis Outcome Score (KOOS). The chi-square test was used to examine the association between BMLs and chondral lesions, and the F test was used to examine the association between BMLs and pain.

Results

Of 241 patients, 58.9% had ≥1 BMLs, and most were located on the medial tibial plateau (MTP; 74.6%) and/or medial femoral condyle (MFC; 28.9%). Most MTP BMLs were submeniscal (56%), and most MFC BMLs extended beyond the meniscus (73%). There were more MFC chondral lesions for patients with any MFC BMLs (P = .01) and submeniscal MFC BMLs (P = .02) versus those without BMLs, and there was no association between BMLs and chondral lesions on the MTP. There was also no association between BMLs and preoperative or postoperative pain scores.

Conclusion

In patients without radiographic evidence of degenerative joint disease who underwent APM, BMLs were found in 58.9% of knees and were primarily located in the medial compartment. There was a borderline statistically significant association between BMLs and chondral lesions for the MFC; however, BMLs were not associated with pain scores preoperatively or at 1 year after surgery.

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).

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.

How Does the Presence of Unstable Chondral Lesions Affect Patient Outcomes After Partial Meniscectomy? The ChAMP Randomized Controlled Trial

BACKGROUND

Chondral lesions are commonly encountered during arthroscopic partial meniscectomy (APM); however, it is unknown how these lesions affect postoperative outcomes.

PURPOSE

The authors compared postoperative outcomes among patients with and without unstable chondral lesions 1 year after APM.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

The authors conducted a secondary analysis of data from the ChAMP (Chondral Lesions and Meniscus Procedures) randomized controlled trial. They compared the following outcomes for patients with unstable chondral lesions that were left in situ and observed (CL-noDeb) versus patients without unstable chondral lesions (NoCL) at 1 year after APM: Western Ontario and McMaster Universities Osteoarthritis Index, Knee injury and Osteoarthritis Outcome Score, visual analog scale for pain, the Short Form Health Survey, range of motion, quadriceps circumference, and effusion. Multivariate linear regression was used to obtain mean differences (MDs) with corresponding 95% CIs adjusted for age, body mass index, and preoperative score (for postoperative scores).

RESULTS

Compared with the CL-noDeb group, the NoCL group had greater improvement in Western Ontario and McMaster Universities Osteoarthritis Index for pain (MD, 7.9, 95% CI: 2.7-13.1), stiffness (MD, 9.1, 95% CI: 1.9-16.3), and physical function (MD, 4.6, 95% CI: 0.1-9.0) and Knee injury and Osteoarthritis Outcome Score for pain (MD, 8.4, 95% CI: 2.7-14.0), function in sport and recreation (MD, 11, 95% CI: 3.0-19.1), and quality of life (MD, 10.4, 95% CI: 2.3-18.5). The NoCL group was less likely than the CL-noDeb group to have an effusion ( P = .02) 1 year after surgery.

CONCLUSION

Patients undergoing APM without unstable chondral lesions had better outcomes than patients with unstable chondral lesions.

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.

Patient Outcomes After Observation Versus Debridement of Unstable Chondral Lesions During Partial Meniscectomy: The Chondral Lesions And Meniscus Procedures (ChAMP) Randomized Controlled Trial

BACKGROUND

It is unknown whether unstable chondral lesions observed during arthroscopic partial meniscectomy (APM) require treatment. We examined differences at 1 year with respect to knee pain and other outcomes between patients who had debridement (CL-Deb) and those who had observation (CL-noDeb) of unstable chondral lesions encountered during APM.

METHODS

Patients who were ≥30 years old and undergoing APM were randomized to receive debridement (CL-Deb group; n = 98) or observation (CL-noDeb; n = 92) of unstable Outerbridge grade-II, III, or IV chondral lesions. Outcomes were evaluated preoperatively and at 8 to 12 days, 6 weeks, 3 months, 6 months, and 1 year postoperatively. Outcome measures included the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee Injury and Osteoarthritis Outcome Score (KOOS), visual analog scale (VAS) pain score, Short Form-36 (SF-36) health survey, range of motion, quadriceps circumference, and effusion. The primary outcome was the WOMAC pain score at 1 year. T tests were used to examine group differences in outcomes, and the means and standard deviations are reported.

RESULTS

There were no significant differences between the groups with respect to any of the 1-year outcome scores. Compared with the CL-Deb group, the CL-noDeb group had improvement in the KOOS quality-of-life (p = 0.04) and SF-36 physical functioning scores (p = 0.01) as well as increased quadriceps circumference at 8 to 12 days (p = 0.02); had improvement in the pain score on the WOMAC (p = 0.02) and KOOS (p = 0.04) at 6 weeks; had improvement in SF-36 physical functioning scores at 3 months (p = 0.01); and had increased quadriceps circumference at 6 months (p = 0.02).

CONCLUSIONS

Outcomes for the CL-Deb and CL-noDeb groups did not differ at 1 year postoperatively. This suggests that there is no benefit to arthroscopic debridement of unstable chondral lesions encountered during APM, and it is recommended that these lesions be left in situ.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

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.

A Case-Control Study Comparing Bone Bruising and Intra-articular Injuries in Patients Undergoing Anterior Cruciate Ligament Reconstruction With and Without Medial Collateral Ligament Tears

Background:

Concomitant injuries can occur in patients with combined anterior cruciate ligament (ACL) and medial collateral ligament (MCL) tears; however, no studies have compared these injuries in patients undergoing ACL reconstruction with an MCL tear to those with an intact MCL.

Purpose:

To compare bone bruising, meniscus tears, and chondral lesions in patients undergoing ACL reconstruction with an MCL tear (cases) to those with an intact MCL (controls).

Study Design:

Case-control study; Level of evidence, 3.

Methods:

Thirty-two cases and 352 controls were identified from a prospective registry. Bone bruising was confirmed on magnetic resonance imaging, and meniscus tears and chondral lesions were confirmed arthroscopically. Demographics and concomitant injuries were compared between cases and controls using exact chi-square tests. Multivariate logistic regression was used to calculate odds ratios (ORs) and 95% CIs adjusted for age, sex, body mass index, and mechanism and type of injury.

Results:

Cases had significantly more contact injuries than controls (58.1% vs 21.3%, P < .0001). The prevalence and odds of bone bruising of the lateral tibial plateau (89.7% vs 84.6%; P = .59; OR, 3.53; 95% CI, 0.45-27.71), lateral femoral condyle (82.8% vs 72.8%; P = .28; OR, 1.94; 95% CI, 0.64-5.88), medial tibial plateau (20.7% vs 31.7%; P = 0.29; OR, 0.53; 95% CI, 0.19-1.53), and medial femoral condyle (6.9% vs 8.3%; P ≥ .999; OR, 1.07; 95% CI, 0.21-5.40) did not differ significantly between cases and controls. The prevalence and odds of lateral meniscus tears (53.3% vs 43%; P = .34; OR, 1.85; 95% CI, 0.76-4.52), medial meniscus tears (31.3% vs 33.5%; P = .85; OR, 0.90; 95% CI, 0.37-2.21), and chondral lesions (16% vs 10.8%; P = .50; OR, 0.70; 95% CI, 0.15-3.21) also did not significantly differ between cases and controls.

Conclusion:

ACL-MCL injuries were most often due to a contact mechanism, whereas ACL tears without associated MCL injury were more frequently due to a noncontact mechanism. However, there were no significant differences in concomitant injuries in ACL-MCL knees versus ACL knees.

How Accurate Are Patients at Diagnosing the Cause of Their Knee Pain With the Help of a Web-based Symptom Checker?

Background:

Researching medical information is the third most popular activity online, and there are a variety of web-based symptom checker programs available.

Purpose:

This study evaluated a patient’s ability to self-diagnose their knee pain from a list of possible diagnoses supplied by an accurate symptom checker.

Study Design:

Cohort study (diagnosis); Level of evidence, 2.

Methods:

All patients older than 18 years who presented to the office of 7 different fellowship-trained sports medicine surgeons over an 8-month period with a complaint of knee pain were asked to participate. A web-based symptom checker for knee pain was used; the program has a reported accuracy of 89%. The symptom checker generates a list of potential diagnoses after patients enter symptoms and links each diagnosis to informative content. After exploring the informative content, patients selected all diagnoses they felt could explain their symptoms. Each patient was later examined by a physician who was blinded to the differential generated by the program as well as the patient-selected diagnoses. A blinded third party compared the diagnoses generated by the program with those selected by the patient as well as the diagnoses determined by the physician. The level of matching between the patient-selected diagnoses and the physician’s diagnoses determined the patient’s ability to correctly diagnose their knee pain.

Results:

There were 163 male and 165 female patients, with a mean age of 48 years (range, 18-76 years). The program generated a mean 6.6 diagnoses (range, 2-15) per patient. Each patient had a mean 1.7 physician diagnoses (range, 1-4). Patients selected a mean 2 diagnoses (range, 1-9). The patient-selected diagnosis matched the physician’s diagnosis 58% of the time.

Conclusion:

With the aid of an accurate symptom checker, patients were able to correctly identify the cause of their knee pain 58% of the time.

Design of a randomized controlled trial to compare debridement to observation of chondral lesions encountered during partial meniscectomy: The ChAMP (Chondral Lesions And Meniscus Procedures) Trial

BACKGROUND

Few studies have examined whether chondral lesions encountered in patients undergoing meniscectomy should be surgically treated. The primary aim of the ChAMP (Chondral Lesions And Meniscus Procedures) Trial is to determine whether there is a difference in knee pain between patients undergoing debridement versus observation of chondral lesions encountered during arthroscopic meniscectomy. This paper describes the rationale and study design for the ChAMP Trial.

METHODS/DESIGN

The ChAMP Trial is a randomized controlled trial of patients aged 30 and older undergoing partial meniscectomy and randomly allocated to debridement (CL-Deb, N=98) or observation (CL-Obs, N=92) of chondral lesions identified during surgery and deemed to be significant (Outerbridge Grade II-IV). Patients and data collectors were unaware of treatment allocation until completion of the study. Patients with surgically insignificant (Outerbridge Grade I) chondral lesions or no chondral lesions were included as a third non-randomized comparison group (NoCL, N=76). The primary outcome is the difference in knee pain assessed by WOMAC (Western Ontario and McMaster Universities Arthritis Index) between the CL-Deb and CL-Obs groups at 1-year after surgery. Secondary outcomes include 1-year differences in additional measures of knee pain, function, symptoms, activity, and quality of life assessed by the WOMAC, KOOS (Knee Injury and Osteoarthritis Outcome Score), visual analog pain scale, and physical exam; as well as general health assessed with the SF-36 (Short-form Health Survey). Increased intraoperative costs associated with the addition of chondral debridement will also be assessed.

DISCUSSION

This study will add to the scant literature regarding management of chondral lesions in patients undergoing meniscectomy and might provide treatment guidance for clinicians and their patients.

Sex-Specific Predictors of Intra-articular Injuries Observed During Anterior Cruciate Ligament Reconstruction

Background:

Male patients tend to have more meniscal and chondral injuries at the time of anterior cruciate ligament (ACL) reconstruction than females. No studies have examined sex-specific predictors of meniscal and chondral lesions in ACL-injured patients.

Purpose:

To identify sex-specific predictors of meniscal and chondral lesions, as well as meniscal tear management, in patients undergoing ACL reconstruction.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Data were collected prospectively from 689 patients (56.2% males) undergoing ACL reconstruction between 2005 and 2014. Predictors of meniscal tears, meniscal tear management, and chondral injuries were determined using multivariate logistic regression models stratified by sex. Predictors were age, body mass index (BMI; 25-29.99 and ≥30 vs ≤24.99 kg/m²), mechanism (contact vs noncontact) and type (high-impact sports [basketball, football, soccer, and skiing] and other sports vs not sports-related) of injury, interval from injury to surgery (≤6 vs >6 weeks), and instability episodes (vs none). Odds ratios and 95% CIs were reported.

Results:

Males had more lateral (46% vs 27.8%; P < .0001) and medial (40.2% vs 31.5%; P = .01) meniscal tears, as well as more lateral (72.1% vs 27.9%; P < .0001) and medial (61.4% vs 38.6%; P = .01) meniscectomies than females. For males, age predicted chondral injuries and medial meniscectomy; BMI ≥30 kg/m² predicted medial meniscal tears; high-impact and other sports predicted medial meniscal tears, medial meniscectomies, and medial meniscal repairs; injuries ≤6 weeks from surgery predicted lateral meniscal repairs; and instability episodes predicted medial meniscal tears, medial tears left in situ, medial meniscectomies, and medial meniscal repairs. For females, age predicted chondral injuries, BMI ≥30 kg/m² predicted lateral meniscectomies and repairs, and instability episodes predicted medial meniscectomies.

Conclusion:

Sex differences were observed. For males, predictors included age, BMI, sports-related injuries, injuries ≤6 weeks from surgery, and instability episodes. For females, predictors included age, BMI, and instability episodes.

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.

Accuracy of a computer-based diagnostic program for ambulatory patients with knee pain

BACKGROUND

Looking up information regarding a medical condition is the third most popular activity online, and there are a variety of web-based symptom-checking programs available to the patient. However, the authors are not aware of any that have been scientifically evaluated as an accurate measure for the cause of one's knee pain.

PURPOSE/HYPOTHESIS

The purpose of this study was to design and evaluate an Internet-based program that generates a differential diagnosis based on a history of knee pain entered by the patient. The hypothesis was that the program would accurately generate a differential diagnosis for patients presenting with knee pain.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 2.

METHODS

A web-based program was created to collect knee pain history and generate a differential diagnosis for ambulatory patients with knee pain. The program selected from 26 common knee diagnoses. A total of 527 consecutive patients aged ≥18 years, who presented with a knee complaint to 7 different board-certified orthopaedic surgeons during a 3-month period, were asked to complete the questionnaire in the program. Upon completion, patients were examined by a board-certified orthopaedic surgeon. Both the patient and physician were blinded to the differential diagnosis generated by the program. A third party was responsible for comparing the diagnosis(es) generated by the program with that determined by the physician. The level of matching between diagnoses determined the accuracy of the program.

RESULTS

A total of 272 male and 255 female patients, with an average age of 47 years (range, 18-84 years), participated in the study. The median number of diagnoses generated by the program was 4.8 (range, 1-10), with this list containing the physician's diagnosis(es) 89% of the time. The specificity was 27%.

CONCLUSION

Despite a low specificity, the results of this study show the program to be an accurate method for generating a differential diagnosis for knee pain.

Defining safe rehabilitation for ulnar collateral ligament reconstruction of the elbow: a biomechanical study

BACKGROUND

Ulnar collateral ligament reconstruction of the elbow using a variety of techniques has been successful in enabling overhead athletes with ulnar collateral ligament insufficiency to return to competition. Most current postoperative rehabilitation programs begin with a period of motion restriction, including limiting elbow extension, that is followed by a transition from elbow strengthening to an interval throwing program, to competition. Motion restrictions early in the postoperative period may increase the risk for contractures. There is limited information to support current motion restrictions.

PURPOSE

(1) To determine strain on the reconstructed ulnar collateral ligament during a rehabilitation protocol that includes passive range of motion, isometric muscle contraction, and varus and valgus torques. (2) To develop guidelines for a safe initial rehabilitation protocol.

STUDY DESIGN

Controlled laboratory study.

METHODS

Eight cadaveric elbows underwent ulnar collateral ligament reconstruction with the docking technique using a gracilis tendon graft. Differential variable reluctance transducers on the anterior and posterior bands of the reconstructed anterior bundle of the ulnar collateral ligament were used to measure strain, while an optical motion tracking system monitored elbow motion. Strain was measured in the following 3 settings: passive range of motion, 22.2 N isometric flexion and extension contractions, and 3.34 N x m varus and valgus torques with the arm at 90 degrees of flexion.

RESULTS

Range of motion from maximum extension to 50 degrees of flexion produced 3% or less strain in both bands of the reconstructed ligament. Forearm rotation did not significantly affect strain in the anterior or posterior bands (P = .336 and P = .357). Strain at 90 degrees approached 7% in the posterior band (upper 95% confidence interval). Isometric muscle contractions had no measurable effect on strain. Varus torques decreased and valgus torques increased strain significantly (P < .05).

CONCLUSION

In the immediate postoperative period, full extension is safe, while flexion beyond 50 degrees may place deleterious strain on the reconstruction. Isometric flexion and extension exercises do not increase ligament strain but may be unsafe at 90 degrees of flexion, while valgus exercises (internal rotation at the shoulder) can increase strain in the reconstructed ligament.

CLINICAL RELEVANCE

The results have implications for the development of appropriate rehabilitation protocols after ulnar collateral ligament reconstructive surgery.