Predicting the deltoid tuberosity index in proximal humerus fractures using fracture characteristics and patient age: development of the LBQ-PHF score

BACKGROUND

The aim of this study was to investigate (1) whether fracture pattern and age are associated with local bone quality (LBQ), and (2) whether a scoring system based on these variables is able to predict LBQ in proximal humerus fractures (PHF).

MATERIALS AND METHODS

A retrospective study was performed of all acute PHF at a Level 2 trauma center with plain radiographs and CT between June 2009 and March 2022. Local bone quality was measured by using the deltoid tuberosity index (DTI). In addition to age and gender, fracture morphology was categorized using the following classification systems: Neer, Resch, AO Foundation/Orthopaedic Trauma Association (AO/OTA), and Hertel/LEGO. Additionally, coronal head alignment was calculated by measuring the head-shaft angle.

RESULTS

Only the Resch classification system revealed a significant relationship between fracture type and bone quality, as there was a significant association between coronal head alignment and DTI (p = 0.001). Valgus head alignment was observed significantly more frequent in patients with low bone quality (p = 0.002). Multinomial logistic regression analysis revealed a significant relative risk ratio for age (RRR = 0.97, [95% CI, 0.94-1], p = 0.039) and a non-significant trend for DTI (RRR = 1.26, [95% CI, 0.96-1.64], p = 0.092) for occurrence of anatomic relative to valgus head alignment. Using a DTI cut-off value of 1.3 instead of 1.4, age and also varus head alignment were identified as significant predictors of LBQ (OR = 1.12, [95% CI, 1.1-1.15], p < 0.001; OR = 0.54, [95% CI, 0.3-0.96], p = 0.037). A scoring system called the LBQ-PHF score (local bone quality in proximal humerus fractures), developed based on these two variables was able to predict LBQ with a sensitivity of 79.2% and a specificity of 86.7%.

CONCLUSION

Age and coronal humeral head alignment are independent predictors of LBQ in PHF. A simple scoring system developed based on these variables is able to assess BQ with solid predictive characteristics.

Humeral torsional side differences after nonoperative treatment of proximal humerus fractures and humeral shaft fractures: clinical and ultrasonographic assessment

BACKGROUND

The purposes of this study were to investigate (1) sonographic humeral torsion (SHT) and side differences (∆SHT), and (2) to determine the relationship between SHT and range of rotational motion (RORM) as well as functional outcome scores of nonoperatively treated proximal humerus fractures (PHF) and humeral shaft fractures (HSF).

METHODS

Between October 2020 and July 2021, consecutive patients with radiographically healed nonoperatively treated PHF and HSF were included in this analysis. Subjective perception of torsional side difference, correlation between SHT and RORM, Subjective Shoulder Value as well as absolute and adjusted Constant Score were determined. Degree of humeral torsional side differences were classified as follows: 0°-15°: minor; > 15°-30°: moderate; > 30°: major. Factors including gender, hand dominance, fracture type, and displacement were also assessed in order to investigate any association between these variables and ∆SHT.

RESULTS

Sixty-five patients with nonoperatively treated PHF (n = 47) and HSF (n = 18) were analyzed. Mean follow-up was 13.2 months (range, 2.1-72.6). The majority (80% (52)) resulted in only minor, 15.4% (10) in moderate, and 4.6% (3) in major torsional side differences. Patients with minor or moderate torsional differences did not perceive any subjective side difference. While RORM correlated fairly to highly with functional outcomes, only very low to low correlation was observed between these measures and SHT and ∆SHT. Gender, fracture displacement, and type of fracture were not related to SHT and ∆SHT. However, significantly greater torsional side differences were observed, when the dominant side was involved (p = 0.026).

CONCLUSION

Nonoperative early functional treatment of proximal humerus and humeral shaft fractures results mainly in only minor humeral torsional side differences. Minor and moderate amounts of torsional side differences might not be perceived by patients.

Diagnostic utility of open biopsy in patients with two culture-negative aspirations in the diagnostic work-up of periprosthetic joint infection

INTRODUCTION

Different approaches have been proposed for bacterial identification in patients with a suspected periprosthetic joint infection (PJI). If a one-stage procedure is considered, a higher rate of preoperative bacterial identification can be achieved if biopsy is included in the diagnostic work-up. The performance of open biopsy (OB) in the context of PJI has not been clearly determined yet. The purpose of this study was to determine the value of an OB added to two consecutive culture-negative joint aspirations during PJI workup.

MATERIALS AND METHODS

We retrospectively analyzed the OB data from a single institution. Patients under PJI work-up of the hip or knee with two culture-negative periprosthetic aspirations who underwent OB were included. Sensitivity and specificity were calculated using the musculoskeletal infection society (MSIS) criteria as gold standard. Patients undergoing urgent irrigation and debridement and patients with history of surgery to the affected joint in the prior 6 weeks were excluded.

RESULTS

126 patients were included in this study. 62 (49.2%) patients had prior revisions, 48 of them due to PJI. The sensitivity and specificity of OB was 69.4% and 89.1%, respectively. The OB procedure led to the identification of the causative germ in 50 out of 126 (40%) cases so they could undergo one-stage (septic) exchange.

CONCLUSION

The OB is a valuable resource if preoperative synovial fluid cultures are negative, a high suspicion of infection persists and a one-stage procedure is preferred. It intends bacteria identification and allows surgeons to evaluate prosthetic complications for further surgical procedures.

Ultrasonographic Measurement of Torsional Side Difference in Proximal Humerus Fractures and Humeral Shaft Fractures: Theoretical Background with Technical Notes for Clinical Implementation

Both nonoperative and operative treatment of proximal humerus fractures (PHF) and humeral shaft fractures can result in torsional side differences. Several measurement methods are available to determine torsional malalignment. While conventional X-ray or computed tomography would entail additional radiation exposure for the patient, and while magnetic resonance imaging might be associated with higher costs and is not suitable in cases of surgically treated fractures due to metal-induced artifacts, the sonographic measurement of humeral torsion represents a readily available and quickly performable measurement method without radiation exposure. Both fully sonographic procedures and sonographically assisted procedures have been described in the literature for this purpose. To date, however, its application in the case of trauma patients, for example those with healed PHF and humeral shaft fractures, is not reported. This viewpoint article aims to provide a concise summary of the literature concerning ultrasonographic indirect measurements of humeral torsional side differences, with technical notes for clinical implementation in case of healed proximal humerus fractures and humeral shaft fractures.

Open latarjet procedure versus all-arthroscopic autologous tricortical iliac crest bone grafting for anterior-inferior glenohumeral instability with glenoid bone loss

PURPOSE

The purpose of this study is to compare the open Latarjet procedure versus the all-arthroscopic autologous tricortical iliac crest bone grafting (AICBG) technique for recurrent anterior-inferior glenohumeral instability with glenoid bone loss.

METHODS

All open Latarjet and AICBG procedures for recurrent anterior-inferior shoulder instability with glenoid bone loss performed at two institutions between September 2015 and April 2019 were retrospectively analyzed. Inclusion criteria were a traumatic etiology, a glenoid surface deficiency >13.5%, and a minimum follow-up (FU) of 18 months. Primary outcomes included the subjective shoulder value, the Western Ontario Shoulder Instability (WOSI), Rowe scores including subdomains, and the four subdomains of the Constant score (pain, activities of daily living, internal rotation, external rotation). Secondary outcomes were subjective shoulder instability, EQ-5D-3 L, pain level on the VAS, level of overall satisfaction, operative time, return-to-work rate, and return-to-sports rate.

RESULTS

Forty-three patients were available for final analysis (Latarjet: n = 21; AICBG: n = 22) at an average FU of 34.9 months (range, 22-66 months). Both techniques provided good outcomes and improved stability. The Rowe score, Rowe-range of motion, and CS-internal rotation (p = 0.008, p<0.001, p = 0.001) were slightly better in the AICBG group. Furthermore, the WOSI physical symptoms subdomain was significantly better (p = 0.04) in the AICBG group, while its total score did not reach statistical significance (p = 0.07). There was no statistically significant difference in the secondary outcomes besides operative time, which was significantly shorter in the Latarjet procedure group (p = 0.04). Overall complication rate was similar in both groups (Latarjet: 9.5% (n = 2), AICBG: 9.1% (n = 2)).

CONCLUSION

Open Latarjet and AICBG procedures provide comparable clinical outcomes except for significantly better Rowe score, Rowe-range of motion, WOSI physical symptoms subdomain, and internal rotation capacity in the AICBG group. However, these results should be carefully interpreted in the context of known minimal clinically important differences of these scores.

Conflicts of interest among patients: do they exist and can they bias patient-reported outcome measures? A survey of shoulder and elbow patients

BACKGROUND

Potential conflicts of interest (COIs) are common among physicians and may bias physician-reported outcome assessment in orthopedic research. It is unclear whether patients have COIs and whether these COIs could affect patient-reported outcome measures (PROMs). The purposes of this study were to investigate (1) the existence of COIs among patients and (2) the potential of these COIs to bias PROMs with a pseudonymized survey among consecutive shoulder and elbow patients.

MATERIALS AND METHODS

Between February and May 2021, 144 shoulder and elbow patients who underwent consultation at our outpatient clinic were included in the survey study. Of these patients, 79.2% (n = 114) completed the 11-item questionnaire. Variables including sex, existence of chronic diseases, level of education, and economic status were also assessed to investigate any association between these variables and patients' perceptions of COIs.

RESULTS

Whereas 33.3% of respondents (n = 38) believe that COIs exist among patients and 28.1% (n = 32) believe that COIs could bias PROMs in general, fewer patients admit to personal COIs (24.6%, n = 28) and COIs biasing their self-assessment (23.7%, n = 27). Patients more frequently suggest COIs in their personal environment, such as among family members or friends (27.2%, n = 31), than in their own medical treatment. Financial factors such as sick pay (34.2%, n = 39) are thought to be the most likely reason for having COIs, followed by interpersonal reasons such as maintaining medical affection or bonds (29.8%, n = 34). Of respondents, 42.1% (n = 48) believe that sole usage of PROMs poses risks in treatment evaluation and only 21% (n = 24) consider PROMs reliable. In addition, 43% of respondents (n = 49) believe that patients should disclose COIs routinely in medical treatment. Multinomial logistic regression analysis revealed that wealthier patients are more likely to believe COIs could bias PROMs (odds ratio for poor vs. middle class, 0.23 [95% confidence interval, 0.053-0.963]; odds ratio for lower-middle class vs. middle class, 0.19 [95% confidence interval, 0.052-0.677]).

CONCLUSIONS

Although the majority of shoulder and elbow patients deny having self-experienced COIs and deny biased PROMs due to COIs in their own medical treatment, a considerable number of patients admit to having experienced both. Further studies might be justified to investigate the actual clinical relevance of patients' COIs and their impact on value-based health care.

High re-revision rate following one-stage exchange for streptococcal periprosthetic joint infection of the hip

INTRODUCTION

This study was undertaken to analyse the outcome of 1-stage exchange in the management of streptococcal periprosthetic joint infection (PJI) of the hip at a single hospital.

METHODS

We identified 30 patients with a streptococcal PJI of the hip who had been treated by 1-stage exchange at our hospital between 2002 and 2017. Postoperative complications and the need for any subsequent re-revision for infection or other reasons were analysed. The Harris Hip Score (HHS) was evaluated at final follow-up.

RESULTS

The mean follow-up was 8.2 years (SD 4.1). The overall re-revision rate for any reason was 53% (16/30) at a mean 5.3 years (SD 0.68 years). Re-revision for infection was 20% (6/30) at a mean 1.8 years (SD 0.74 years). All re-revisions for PJI (6/6; 100%) were for relapse of the streptococcal infection. At final follow-up, the mean HHS was 68 points (SD 20).

CONCLUSIONS

The rate of re-revision after 1-stage exchange for streptococcal PJI is high. Eradication of a streptococcal PJI of the hip remains challenging. Further extensive and comparative studies between 1-and 2-stage exchange are encouraged.

Inter- and intraobserver reliability of morphological Mutch classification for greater tuberosity fractures of the proximal humerus: A comparison of x-ray, two-, and three-dimensional CT imaging

BACKGROUND

The objective of this study was to investigate inter- and intraobserver reliability of the morphological Mutch classification for greater tuberosity (GT) fragments in consecutive proximal humerus fractures (PHF) regardless of the number of parts according to the Codman classification system for three different imaging modalities (plain radiographs, two-dimensional [2-D] computed tomography [CT], and reformatted, three-dimensional [3-D] CT reconstruction).

MATERIALS AND METHODS

One hundred thirty-eight consecutive PHF with GT involvement were identified between January 2018 and December 2018 in a supraregional Level 1 trauma center. GT morphology was classified by three blinded observers according to the morphological Mutch classification using the picture archiving and communication software Visage 7.1 (Visage Imaging Inc., San Diego, CA, USA). Fleiss' and Cohens' kappa were assessed for inter- and intraobserver reliability. Strength of agreement for kappa (k) values was interpreted according to the Landis and Koch benchmark scale.

RESULTS

In cases of isolated GT fractures (n = 24), the morphological Mutch classification achieved consistently substantial values for interobserver reliability (radiograph: k = 0.63; 2-D CT: k = 0.75; 3-D CT: k = 0.77). Moreover, use of advanced imaging (2-D and 3-D CT) tends to increase reliability. Consistently substantial mean values were found for intraobserver agreement (radiograph: Ø k = 0.72; 2-D CT: Ø k = 0.8; 3-D CT: Ø k = 0.76). In cases of multi-part PHF with GT involvement (n = 114), interobserver agreement was only slight to fair regardless of imaging modality (radiograph: k = 0.3; 2-D CT: k = 0.17; 3-D CT: k = 0.05). Intraobserver agreement achieved fair to moderate mean values (radiograph: Ø k = 0.56; 2-D CT: Ø k = 0.61; 3-D CT: Ø k = 0.33).

CONCLUSION

The morphological Mutch classification remains a reliable classification for isolated GT fractures, even with 2-D or 3-D CT imaging. Usage of these advanced imaging modalities tends to increase interobserver reliability. However, its reliability for multi-part fractures with GT involvement is limited. A simple and reliable classification is missing for this fracture entity.

Nonsensus in the treatment of proximal humerus fractures: uncontrolled, blinded, comparative behavioural analysis between Homo chirurgicus accidentus and Macaca sylvanus

OBJECTIVE

To investigate the inter-rater reliability of Barbary macaques compared with an expert group of surgeons for the choice of treatment and predicted outcome of proximal humerus fractures.

DESIGN

Uncontrolled, blinded, comparative behavioural analysis.

SETTING

Germany and United States.

PARTICIPANTS

10 blinded experts in the field of orthopaedic trauma surgery (Homo chirurgicus accidentus), with special focus on upper extremity surgery from Germany and the US, and five Barbary macaques (Macaca sylvanus) from a semi-free range enclosure.

MAIN OUTCOME MEASURES

The reliability of agreement between raters assessed with Fleiss' ĸ.

RESULTS

Barbary macaques seem to have inferior inter-rater reliability in comparison with experts for choice of treatment (non-surgical v surgical), but for the geriatric age group most frequently affected by proximal humeral fractures, they performed similarly to the experts in their choices of treatment and choice of surgical procedure. Agreement about predicted outcome was poor among the macaques and slight among the experts. All experts almost always predicted the outcome incorrectly and tended to underestimate it. While only 4 (4.4%) of 90 experts' predictions were correct, 13 (28.9%) of 45 macaques' predictions were correct.

CONCLUSIONS

Consensus on treatment and expected outcomes of proximal humeral fractures is lacking even beyond the human species. Although Barbary macaques tend to predict the clinical outcome more accurately, their reliability to assist surgeons in making a consistent decision is limited. Future high quality research is needed to guide surgeons' decision making on the optimal treatment of this common injury.

Noise levels during total hip arthroplasty: the silent health hazard

BACKGROUND

While there is an enormous amount of data on various surgical aspects of total hip arthroplasty (THA), there is only limited literature on the health hazards incurred by the surgical team. Since THA surgery produces noise, exposure over a long period of time may lead to gradual hearing loss which is known as noise-induced hearing loss.

METHODS

We investigated the noise levels during THA and compared it with the maximum allowed limits at the workplace in the United Kingdom. In collaboration with specialised audio engineers, we analysed the noise levels during various steps of performing 7 uncemented THA.

RESULTS

The results showed that the noise levels were close to the allowed limits for a workplace in the UK.

CONCLUSION

Hospitals and staff who work in orthopaedic operating theatres should be aware of this risk and precautions should be put in place.

Distal Biceps Tendon Repair Using a Modified Double-Incision Technique: Patient-Reported Outcomes With 10-Year Follow-up

Background:

In the setting of complete distal biceps tendon rupture, surgical repair has become the standard of care to restore optimal elbow function, but the optimal approach and method of tendon fixation are still subjects of debate and have remained controversial for more than half a century.

Purpose:

To evaluate patient-reported long-term outcomes after distal biceps tendon repair using a modified double-incision technique.

Study Design:

Case series; Level of evidence, 4.

Methods:

We reviewed primary distal biceps tendon repairs after isolated tendon rupture using the modified muscle-splitting double-incision approach and transosseous suture fixation technique described by Morrey et al (1985), which had been performed at our level 1 trauma center between January 2000 and December 2013. Outcome measures included the subjective elbow value (SEV), the Oxford Elbow Score (OES) with its 3 domains (function, pain, and social-psychological), a self-performed hook test, and the 3-level version of the EuroQoL 5-dimensional instrument (EQ-5D-3L) as a measure of health status. Levels of overall satisfaction were determined by asking whether the patient would consent to the operation again. In addition, patients were asked to report any complications.

Results:

A total of 30 patients met the inclusion criteria, and 25 patients were available for the survey. Mean age at the time of rupture was 47 years. All patients were male. Mean follow-up was 120 months (range, 57-207 months). The follow-up rate was 83.34%. The following outcome results were obtained: SEV, 88.16% ± 25.18%; OES, 43.80 ± 10.56 out of 48 points; OES Pain, 92.50% ± 23.03%; OES Function, 92.25% ± 22.19%; OES Social-Psychological, 89% ± 23.68%; EQ-5D-3L, 0.93 ± 0.21. All patients described a negative hook test. Patient-reported complications included painless limitation in forearm rotation in 8% of patients (n = 2); reduced flexion and forearm rotation strength with and without pain in 8% (n = 2) and 4% (n = 1), respectively; synostosis after 1 year requiring revision surgery in 4% (n = 1); and transient wrist drop in 4% (n = 1). The overall complication rate was 28% (7/25), and 96% (n = 24) would consent to the operation again.

Conclusion:

Despite the cited approach-related morbidity, we report an excellent patient-reported long-term outcome for the double-incision distal biceps repair technique.

Correlation between Oxford Elbow Score and Single Assessment Numeric Evaluation: Is one simple question enough?

BACKGROUND

The aim of this study is to evaluate the correlation between the Oxford Elbow Score (OES) and Single Assessment Numeric Evaluation (SANE). To date, there has been no study investigating a correlation between this patient-reported outcome measure and SANE.

METHODS

Between December 2018 and February 2019, all patients who underwent consultation for elbow pathology and completed the OES and SANE were retrospectively analyzed. Pearson correlation coefficient between the OES and SANE was calculated. Variables, including age, gender, diagnosis, chief complaint for consultation, and pain level on the visual analog scale (VAS), were also collected, and a mixed effects linear regression model was used to identify predictors for higher correlation.

RESULTS

One hundred seven consultations of 86 patients were analyzed. The mean SANE and OES were 62.13% and 60.36%, respectively. Both scores correlated highly (r = 0.903). Across the OES domains, the strongest correlation was found between SANE and the OES psychosocial domain (r = 0.885). High correlations were also found between SANE and the OES function (r = 0.847) and OES pain (r = 0.804) domains. All values were statistically significant (P < .001). A moderate inverse correlation was found between SANE and VAS (r = -0.631). Aside from SANE, the VAS was identified as a significant predictor of the OES.

CONCLUSION

SANE correlates highly with the OES. It is an easy tool for assessing the condition of the elbow joint, can be obtained without any license or payment restrictions, and should be considered as a worthwhile adjunct to currently used scores.

[Fracture diagnosis: upper extremities : Shoulder and shoulder girdle]

BACKGROUND

The shoulder girdle is a chain of bones and joints which connect the upper extremity to the axial skeleton. The shoulder as a biomechanical unit has a remarkable range of motion and is therefore frequently prone to injuries of the three major joints (sternoclavicular joint, acromioclavicular joint, glenohumeral joint) and the bony elements (clavicle, scapula, humerus). Projection radiography is still the first imaging modality for injuries of the shoulder and usually sufficient for initial diagnosis and injury classification. Computed tomography (including 3D reconstructions) and magnetic resonance imaging provide additional useful information for the detection of accompanying soft-tissue injury, for surgical planning and in cases of complex anatomy (e.g., scapular fractures).

PURPOSE

We aim to describe the fundamentals of injuries of the shoulder girdle and the proximal humerus with special emphasis on radiological diagnostics.

MATERIALS AND METHODS

A selective PubMed literature search was performed using the following terms: "sternoclavicular joint dislocation", "clavicle fracture", "acromioclavicular joint injury", "scapular fracture", "shoulder dislocation", "proximal humerus fracture", and "shoulder girdle injuries".

RESULTS

The article describes the basics of the anatomy, the trauma mechanism and the epidemiology of the most common injuries of the shoulder girdle and the proximal humerus. Special emphasis is given to radiological diagnostics, including basic projection radiography and advanced cross-sectional imaging.

Screw fixation for syndesmotic injury is stronger and provides more contact area of the joint surface than TightRope®: A biomechanical study

BACKGROUND

The rupture of syndesmotic ligaments is treated with a screw fixation as the gold standard. An alternative is the stabilization with a TightRope®. A couple of studies investigated the different clinical outcome and some even looked at the stability in the joint, but none of them examined the occurring pressure after fixation.

OBJECTIVE

Is there a difference in pressure inside the distal tibiofibular joint between a screw fixation and a TightRope®? Does the contact area differ in these two treatment options?

METHODS

This biomechanical study aimed to investigate the differences in fixation of the injured syndesmotic ligaments by using a fixation with one quadricortical screw versus singular TightRope® both implanted 1 cm above the joint. By using 12 adult lower leg cadaveric specimens and pressure recording sensor, we recorded the pressure across the distal tibiofibular joint. Additionally we measured the contact surface area across the joint.

RESULTS

The mean of the pressure across the distal tibiofibular joint from the start of the insertion of the fixation device to the complete fixation was 0.05 Pascal for the TightRope® and 0.1 for the screw (P= 0.016). The mean of the maximum pressure across the joint (after completion of fixation and releasing the reduction clamp) was 1.750 mega Pascal with the screw fixation and 0.540 mega Pascal with TightRope® (P= 0.008). The mean of the measured contact area of the distal tibiofibular joint after fixation was 250 mm2 in the TightRope® group and of 355 mm2 in the screw fixation (P= 0.123).

CONCLUSIONS

The screw fixation is stronger and provides a larger surface contact area, which leads us to the conclusion that it provides a better stability in the joint. While previous clinical studies did not show significant clinical difference between the two methods of fixation, the biomechanical construct varied. Long term clinical studies are required to establish whether this biomechanical distinction will contribute to various clinical outcomes.

Midterm Results After Tantalum Cones in 1-Stage Knee Exchange for Periprosthetic Joint Infection: A Single-Center Study

BACKGROUND

The use of tantalum cones to reconstruct extensive bone defects in revision total knee arthroplasty has been established. We aimed to evaluate the midterm results after 1-stage knee exchange for periprosthetic joint infection using tantalum cones.

METHODS

Seventy-two patients (mean age, 70 ± 8.2 years) treated with a 1-stage exchange for infected total knee arthroplasty using porous tantalum cones, between 2011 and 2016, were retrospectively included. Either rotating or pure hinge system in combination with femoral and/or tibial cones was used. Survivorship analysis (septic and aseptic) was performed. Prospectively, functional outcome was assessed at a mean follow-up of 49.9 ± 18.8 months (range, 24-88).

RESULTS

A total of 15 patients (21%) were rerevised, 8 (11.1%) for infection and 7 (10%) for aseptic loosening, requiring cone exchange in 12 patients (17%). Cone-related survival free from any revision was 83% ± 3.8 standard deviation (95% confidence interval, 74-90), and infection-free survival was 89% ± 4.2 standard deviation (95% confidence interval, 76-93). No significant correlation was reported between the types of prosthesis used (P = .8) or implanted cones and failure (P = .6). History of a previous septic revision increased the risk of cone revision after the index surgery (P < .001). Preoperative Hospital for Special Surgery knee score improved from 47 ± 16 (range, 14-87) to 60 ± 17 (range, 24-84) points at the latest follow-up.

CONCLUSION

First study reports on outcomes of the 1-stage exchange using tantalum cones for knee periprosthetic joint infection with additional severe bone loss. Midterm cone-related and infection-free survival offered good results and provided reasonable functional outcomes.

Effect of Femoral Antetorsion on Tibiofemoral Translation and Rotation in the Anterior Cruciate Ligament Deficient Knee

We aimed to investigate how increased or decreased femoral antetorsion would affect the biomechanics of the knee in an anterior cruciate ligament (ACL)-deficient cadaveric model. We hypothesized that external or internal rotation of the distal femur, achieved through a femoral osteotomy, would affect the magnitude of tibiofemoral translation and rotation. Navigated measurements of tibiofemoral translation and rotation during the anterior drawer, Lachman, and pivot shift tests were performed on six whole-body cadaveric specimens in each of the following four conditions: native, ACL-deficient knee, ACL-deficient knee and 20-degree internal distal femur rotation, and ACL-deficient knee and 20-degree external distal femur rotation. Increased femoral antetorsion significantly reduced anterior tibial translation in the ACL-deficient knee during the anterior drawer, Lachman, and pivot shift tests (p < 0.05). Conversely, decreasing femoral antetorsion resulted in an increase in anterior tibial translation in the anterior drawer (nonsignificant), Lachman (p < 0.05), and pivot shift (p < 0.05) tests. Internally rotating the distal femur significantly reduced the magnitude of tibial rotation during the pivot shift test in the ACL-deficient knee (p < 0.05), whereas external rotation of the distal femur significantly increased tibial rotation (p < 0.05). The magnitude of femoral antetorsion affects tibiofemoral translation in an ACL-deficient cadaveric mode. Internally rotating the distal femur 20 degrees reduced the magnitude of tibial translation and rotation similar to that of the native knee, whereas externally rotating the distal femur aggravated translational and rotational instability.

Higher sensitivity of swab polymerase chain reaction compared with tissue cultures for diagnosing periprosthetic joint infection

PURPOSE

The aim of this study was to assess the diagnostic accuracy of swab polymerase chain reaction (PCR) compared with tissue culture as the current gold standard.

METHODS

Forty-one consecutive patients were prospectively enrolled undergoing revision arthroplasty due to septic and aseptic reasons. Infection classification was done according to the criteria of the Musculoskeletal Infection Society. Intraoperatively, tissue samples of the periprosthetic membrane were collected for culture analysis, and swabs were taken from the accessible implant surface to perform 16S ribosomal RNA PCR. The diagnostic performance of swab PCR and tissue cultures was determined.

RESULTS

Of the 41 patients, 53.7% ( n = 22) had a periprosthetic joint infection (PJI) and 46.3% ( n = 19) an aseptic loosening. Swab PCR showed a higher sensitivity than tissue cultures (86.4% vs. 68.2%), while the specificity was equal (89.5%). The area under the curve was 0.79 for tissue cultures and 0.88 for swab PCR.

CONCLUSIONS

In this first investigation of swab PCR for diagnosing PJI, this procedure revealed a higher sensitivity for diagnosing PJI compared with tissue cultures. Because swab PCR is easily implementable and does not require special equipment, it can potentially improve the diagnosis of PJI.

Axillary Artery Dissection and Thrombosis after Closed Proximal Humerus Fracture - a Rare Interdisciplinary Challenge

BACKGROUND

Proximal humerus fractures account for 4 - 6% of all fractures and are a common result of low-energy trauma in the elderly. Concomitant neurovascular injury of the neighboring axillary artery and brachial plexus is a rarity, but has enormous impact on therapy, rehabilitation and prognosis. Diagnosis of axillary artery injury may be delayed due to its varied clinical presentation and lead to prolonged ischemia, distal necrosis and even loss of limb. Thorough clinical examination, high suspicion and identification of known predictors can be helpful in early diagnosis of this rare injury.

PATIENTS/MATERIAL AND METHODS

We report a case of an intoxicated 76-year-old male who sustained a dislocated proximal humerus fracture, resulting in concomitant brachial plexopathy and axillary artery dissection with secondary thrombosis after a low-energy fall from standing height. Due to mistriage as a neurological emergency the somnolent patient presented under delayed circumstances at our traumatological emergency department, demonstrating pain, paleness, paralysis, paresthesia and non-palpable wrist pulses. Diagnosis was made through high suspicion after clinical examination with the aid of CT angiography. Emergent open reduction and anatomic shoulder hemiarthroplasty was performed followed by axillobrachial interposition grafting using a reversed saphenous vein graft and brachial plexus exploration.

RESULTS

The surgical treatments were uncomplicated. The affected limb remains viable at 6-week follow-up; however, active shoulder function is limited due to residual brachial plexopathy.

CONCLUSION

Despite early diagnosis and management of this rare injury, the prognosis for functional recovery is guarded and largely dictated by the extent of neurological injury in the setting of concomitant brachial plexopathy. Brachial plexopathy is highly associated with axillary artery injury and its impact often underestimated in comparison due to its non-limb-threatening nature in the acute setting. Future studies should focus on the long-term prognosis for functional recovery in patients with this rare injury pattern.

[Torsional malalignment of the humerus]

The torsion of the humerus describes the physiological rotation of the humerus around its longitudinal axis. Various clinical and radiological methods for measurement have been described. The computed tomography method is currently the gold standard. The angle between the humeral head axis and the transepicondylar axis is measured. This angle is called retroversion. Values of retroversion vary between 10° and 40°. For the treatment of many humeral pathologies, a precise reconstruction of the anatomical retroversion is required. The retroversion of the humerus has to be considered in shoulder arthroplasty, in fracture situations and also in planning correction of posttraumatic deformities. If an orientation to the original anatomical landmarks of the humerus is no longer possible, an orientation to the contralateral side is recommended.

Monocortical fixation of the coracoid in the Latarjet procedure is significantly weaker than bicortical fixation

PURPOSE

A crucial step of the Latarjet procedure is the fixation of the coracoid process onto the glenoid. Multiple problems associated with the fixation have been described, including lesions of the suprascapular nerve due to prominence of the screw or bicortical drilling. The purpose of the present study was to evaluate whether monocortical fixation, without perforating the posterior glenoid cortex, would provide sufficient graft stability.

METHODS

Coracoid transfer was performed in 14 scapula models (Sawbones^®, Composite Scapula, 4th generation). Two groups were assigned: in one group, fixation was achieved with two screws that did not perforate the posterior cortex of the glenoid neck (monocortical fixation), in the other group, fixation was achieved with perforation of the posterior cortex (bicortical fixation). The ultimate failure load and mode of failure were evaluated biomechanically.

RESULTS

Monocortical fixation was a significantly weaker construct than bicortical fixation (median failure load 221 N, interquartile range 211-297 vs. median failure load 423 N, interquartile range 273-497; p = 0.017). Failure was either due to a pullout of the screws from the socket or a fracture of the glenoid. There was no significant difference in the mode of failure between the two groups (n.s.).

CONCLUSION

Monocortical fixation was significantly weaker than bicortical fixation. However, bicortical drilling and overly long screws may jeopardize the suprascapular nerve. Thus, anatomic knowledge about the safe zone at the posterior rim of the glenoid is crucial. Until further research has evaluated, if the inferior stability is clinically relevant, clinicians should be cautious to use a monocortical fixation technique for the coracoid graft.

Intraoperative computer-assisted prediction of intraarticular contact pressures in the knee during high tibial osteotomy

OBJECTIVES

To develop an accurate intraoperative method to estimate changes in intraarticular contact pressures during high tibial osteotomy (HTO).

METHODS

Changes in knee alignment and pressure were monitored in real time in seven cadaver specimens that received HTO. Intraarticular contact pressure (N/mm² ) in each knee compartment was estimated based on extraarticularly acquired data (leg alignment, correction, and ankle tilt) and based on the application of an axial force of half bodyweight (400-450 N).

RESULTS

Contact pressure estimation was more accurate in the lateral compartment (R²  = 0.940) than in the medial compartment of the knee (R²  = 0.835). The optimism-corrected R² was 0.936 for the lateral compartment and 0.821 for the medial compartment.

CONCLUSIONS

We have established a framework for estimating the change in intraarticular contact pressures based on extraarticular data. This research could be helpful in generating appropriate algorithms to estimate joint alignment changes based on applied loads.

[Proximal humeral fractures-Where do we stand today? : Comments on the "Proximal fracture of the humerus evaluation by randomization (PROFHER)" study]

The PROFHER study is a multicenter randomized controlled trial of 250 out of 1250 patients assessed for eligibility with dislocated proximal humeral fractures with involvement of the surgical neck. These patients were randomized either for surgery or conservative treatment. Patients with comorbidities that precluded surgery, lack of mental capacity, luxation fractures or clear indications for surgery from the authors' perspective were excluded. To evaluate the outcome, standardized self-assessment methods were used (patient reported outcome [PRO]), including the Oxford shoulder score (OSS). The results showed no differences in the primary and secondary self-assessment outcome scores after both 2 and 5 years. Although no significant differences could be detected between both groups, no clear statement could be deduced from the PROFHER study with respect to which patients would benefit from an operative treatment. Nevertheless, the PROFHER study provides a valuable and important addition to the literature on this heavily debated topic. The purpose of this review is to critically evaluate the PROFHER study within the existing literature regarding inclusion of patients, fracture treatment and evaluation of the results.

Classification of humeral head pathomorphology in primary osteoarthritis: a radiographic and in vivo photographic analysis

BACKGROUND

The purpose of this study was to characterize the pathologic changes of the osteoarthritic humeral head.

METHODS

The study included 55 patients with primary osteoarthritis who underwent anatomic shoulder arthroplasty. Several radiologic parameters (radiography, magnetic resonance imaging) were assessed. Humeral head deformity in the transverse plane and humeral cartilage erosion in the coronal plane were chosen for photographic measurements from the resected humeral heads.

RESULTS

In the coronal plane, 82% of patients presented with an aspherical humeral head shape with a significantly longer caudal osteophyte. In the transverse plane, 50% of all patients showed a decentered apex. Patients with an aspherical humeral head shape in the transverse plane showed an aspherical humeral head shape in the coronal plane in 94% and a significantly longer osteophyte than patients with spherical humeral head shape, showing a 3-dimensional deformity of the humeral head during progression of primary osteoarthritis. Patients with an osteophyte length between 7 and 12 mm were associated with a glenoid type B2 in 30% and a decentered apex in the transverse plane in 38%. Patients with a humeral osteophyte longer than 13 mm were significantly more frequently associated with a type B2 glenoid (71%; P < .0001) and a decentered apex in the transverse plane in 52%.

CONCLUSION

It seems that the progression of primary osteoarthritis of the glenohumeral joint is characterized by an increasing 3-dimensional deformity of the humeral head related to the glenoid morphology. We therefore propose an extended Samilson-Prieto classification with type A (spherical) and type B (aspherical) and grade I-IV osteophytes.

[Shoulder dislocations in elderly patients]

In contrast to shoulder dislocations in younger patients, anterior shoulder dislocation in the elderly is often associated with concomitant injuries to the rotator cuff and fractures. There is also frequent involvement of the brachial plexus or peripheral nerves. After closed reduction and a short period of immobilization, physiotherapy should be performed to restore mobility and strength. The evaluation of the rotator cuff is essential for further treatment decisions. The majority of patients are classically treated conservatively. Elderly patients with accompanying rotator cuff lesions and failed conservative therapy can benefit from a surgical intervention. Reconstructive interventions of the rotator cuff should be principally considered; however, some individuals may benefit from a reverse prosthesis in this elderly subgroup of patients. The challenge for the treating surgeon is to exactly define the structural injury of the shoulder (which may include pre-existing lesions) and to select the optimal treatment option.

Fatty degeneration of the deltoid muscle associated with displaced proximal humerus fractures

INTRODUCTION

The use of reverse shoulder arthroplasty (RSA) has increased dramatically over the last two decades, with many surgeons now indicating RSA for the acute management of displaced proximal humerus fractures (PHF) in the elderly. RSA relies on adequate deltoid muscle function to obtain a good outcome, yet no literature to date exists which discusses preoperative assessment of deltoid structure prior to RSA. The purpose of this study was to assess for preoperative fatty deltoid-degeneration in patients with displaced PHF.

MATERIALS AND METHODS

We reviewed the axial CT scans of 100 consecutive patients with a displaced PHF. Fatty degeneration within each of the three deltoid-heads was graded at three levels, according to Goutallier and colleagues. Fractures were classified according to Neer.

RESULTS

Seventy-nine percent of the patients were female, 75% showed 3 or 4 parts fractures. The average cross-sectional area of the posterior deltoid was greatest-representing 37%, 40% and 42% of total area at each level, respectively. Severe fatty degeneration (Stages 3 and 4) was observed in the posterior deltoid only (26%). Absence of fatty degeneration (Stage 0) was observed in < 25% of cases. The Inter-Observer-Reliability for the continuous variables proved to be high.

CONCLUSION

Preoperative deltoid fatty degeneration is common in displaced PHF in the elderly. Because CT is commonly obtained to assess fracture morphology and for preoperative planning purposes, it is an ideal tool to assess the deltoid additionally. Future studies are warranted to determine whether preoperative fatty infiltration of the deltoid correlates with mid and long term functional outcomes when RSA is used acutely to manage a PHF.

LEVEL OF EVIDENCE

Level IV-consecutive case series.

Improving the human-robot interface for telemanipulated robotic long bone fracture reduction: Joystick device vs. haptic manipulator

OBJECTIVES

Intramedullary nailing is the treatment of choice for femoral shaft fractures. However, there are several problems associated with the technique, e.g. high radiation exposure and rotational malalignment. Experimental robotic assistance has been introduced to improve the quality of the reduction and to reduce the incidence of rotational malalignment. In the current study, we compare two devices for control of the fracture fragments during telemanipulated reduction.

METHODS

Ten male and ten female subjects were asked to participate as examiners in this experiment. A computer program was developed to render and manipulate CT-based renderings of femur fracture bone fragments. The user could manipulate the fragments using either a simple joystick device or a haptic manipulator. Each examiner performed telemanipulated reduction of 10 virtual fracture models of varying difficulty with each device (five in a 'training phase' and five in a 'testing phase'). Mixed models were used to test whether using the haptic device improved alignment accuracy and improved reduction times compared to using a joystick.

RESULTS

Reduction accuracy was not significantly different between devices in either the training phase or the testing phase (P > 0.05). Reduction time was significantly higher for the Phantom device than for the Joystick in the training phase (P < 0.0001), but it was no different in the testing phase (P = 0.865). High spatial ability with electronics had a significant effect on the alignment of fracture reduction and time to reduction.

CONCLUSIONS

The Joystick and the Phantom devices resulted in similarly accurate reductions, with the Joystick having an easier learning curve. The Phantom device offered no advantage over the Joystick for fracture telemanipulation. Considering the high cost of the Phantom device and the lack of a demonstrable advantage over the Joystick, its use is not justified for implementation in a fracture telemanipulation workflow. The Joystick remains as a low-cost and effective device for developing 3D fracture telemanipulation techniques.

Comparison of algorithms for automated femur fracture reduction

PURPOSE

We designed an experiment to determine the comparative effectiveness of computer algorithms for performing automated long bone fracture reduction.

METHODS

Automated reduction of 10 3D fracture models was performed using two computer algorithms, random sample matching (RANSAM) and Z-buffering (Z-Buffer), and one of five options of post-processing: none; iterative closest point algorithm (ICP); ICP-X1; ICP-X2; and ICP-X3. We measured the final alignment between the two fragments for each algorithm and post-processing option.

RESULTS

The RANSAM algorithm combined with postprocessing algorithm ICP-X1 or ICP-X3 resulted in the most accurate fracture reduction in the translational plane. No discernible difference was observed in the rotational plane. Automated reduction had more accurate translational displacement than telemanipulated manual reductions.

CONCLUSION

This study supports the use of the RANSAM algorithm for automated fracture reduction procedures. The use of ICP algorithms provides further optimization of the initial reduction.

Nine-year outcome after anatomic stemless shoulder prosthesis: clinical and radiologic results

BACKGROUND

Several stemless shoulder implants are available on the market, but only a few studies have presented results with sufficient mid- to long-term follow-up. The present study evaluated clinical and radiologic outcomes 9 years after anatomic stemless shoulder replacement.

METHODS

This is a prospective cohort study evaluating the stemless shoulder prosthesis since 2005. Anatomic stemless shoulder replacement using a single prosthesis was performed in 49 shoulders; 17 underwent total shoulder replacement, and 32 underwent hemiarthroplasty. Forty-three patients were clinically and radiologically monitored after a mean of 9 years (range, 90-127 months; follow-up rate, 88%). The indications for shoulder replacement were primary osteoarthritis in 7 shoulders, post-traumatic in 24, instability in 7, cuff tear arthropathy in 2, postinfectious arthritis in 1, and revision arthroplasty in 2.

RESULTS

The Constant-Murley Score improved significantly from 52% to 79% (P < .0001). The active range of motion also increased significantly for flexion from 101° to 118° (P = .022), for abduction from 79° to 105° (P = .02), and for external rotation from 21° to 43° (P < .0001). Radiologic evaluation revealed incomplete radiolucency in 1 patient without clinical significance or further intervention. No revision caused by loosening or countersinking of the humeral implant was observed.

CONCLUSIONS

The 9-year outcome after stemless shoulder replacement is comparable to that of third- and fourth-generation standard shoulder arthroplasty.

Combined Fluoroscopic and Arthroscopic Detection and Removal of a Foreign Body Lost During Elective Shoulder Arthroscopy: A Case Report

Introduction:

We report a case of a lost metal platelet from a radiofrequency ablation probe (VAPR VUE Radiofrequency System, Cool Pulse 90, DePuy, Synthes, Switzerland) in the shoulder joint during elective arthroscopic cuff repair. To the best of our knowledge, this kind of an incident during elective arthroscopy has not been described in the literature so far. In addition, we present an algorithm on how to deal with such an incident.

Case Report:

A 69-year-old woman underwent an arthroscopic subacromial decompression and rotator cuff repair for a torn supraspinatus tendon. While performing the subacromial decompression and after swapping the portals from lateral to posterior, the metal platelet of the electrocautery device got detached from the instrument and lost in the operation field. Several attempts to visualize the lost platelet with the camera failed. Finally, intraoperative fluoroscopic imaging was used to detect the platelet. To confirm the definitive whereabouts of the platelet, two spinal needles were positioned perpendicular to another under x-ray control, both pointing at the missing platelet. After determining the exact location, the platelet could finally be visualized with the camera and removed. Due to this incident, the operation time was extended extensively, and the patient as well as the theatre team was exposed to an unnecessary amount of radiation.

Conclusion:

This report indicates that an extraordinary incident such as the detachment of a component of the arthroscopic equipment during surgery is possible and should be kept in mind by the surgeon. Therefore, we believe that it is essential to perform a test of integrity at least at the end of every operation. In addition, we are presenting an algorithm on how to deal with the situation of a lost foreign body during arthroscopy, which can be applied to any joint.

Robotic guided waterjet cutting technique for high tibial dome osteotomy: A pilot study

BACKGROUND

Oscillating saws generate high levels of heat (up to 150°C), which can lead to tissue necrosis, delayed healing and infection. Abrasive waterjet-cutting techniques have been described as a new tool to perform bone cuts, with less heat generation.

METHODS

Four lower-limbs of four human alcohol conserved cadavers were tested. Navigation references were attached to the tibia and an intraoperative fluoroscopy-based 3D scan was obtained. A 1.2 mm diameter nozzle was attached to a robotic arm, which was guided to follow a pre-specified path. In addition, a self-designed jet-absorber was applied to protect the posterior neurovascular structures. Magnesium was added as an abrasive substance to improve the cutting ability of the waterjet.

RESULTS

In all four cadavers, the osteotomies could be carried out as planned, resulting in smooth cut surfaces. No damage to the soft-tissues was observed.

CONCLUSIONS

The advantages of abrasive waterjet-cutting give it great potential in orthopaedic surgery. A current disadvantage is the amount of magnesium solute that is left on the surgical field and can be harmful to the patient.

[Limb salvage or amputation after severe trauma to the lower extremities : Evidence from the LEAP Study]

Deciding between reconstruction and primary amputation after severe high-energy trauma to the lower extremities is difficult and consequential. The Lower Extremity Assessment Project (LEAP) prospectively included and investigated patients with severe, limb-threatening injuries below the femur, with third-grade open fractures, defined soft-tissue damage and amputation wounds. This paper aims to review the key results of the LEAP study, which were published in several parts, in due consideration of the newer relevant literature, and to deduce the consequences for clinical practice. The main results are as follows: No score is sufficiently reliable to predict the success of reconstruction. Loss of muscle seems to be more momentous than loss of bone. Any accompanying injuries that should be taken into account in the individual treatment concepts are crucial to the results, in addition to comorbidities and other individual patient-related factors, such as alcoholism, smoking, insurance, and social background. Psychological impairment is frequent after these injuries and should therefore be addressed regularly with regard to rehabilitation.

[Tendinopathies of the shoulder and elbow]

BACKGROUND

Tendinopathies of the shoulder and elbow joint are a common problem. According to the current state of knowledge tendinopathies can be separated into acute and chronic tendinitis as well as degenerative tendinosis.

ORIGIN

The causes of tendinopathy can be intrinsic, extrinsic or a combination of both. A false straining or overuse with repetitive microtrauma is often the cause. Particularly affected are tendons of the rotator cuff, the long biceps tendons and lower arm extensors.

TREATMENT

Priority is given to conservative appproaches for these disease processes. Following appropriate diagnostics the pain can be reduced and function can be improved by specific training. When conservative treatment is unsuccessful and in the presence of certain indications, a surgical approach should be considered. In these cases a structural damage of the tendon often already exists, which could have resulted from the tendinopathy. The structural damage must be considered as a separate entity and differentiated from the tendinopathy.

Glenoid deformity in the coronal plane correlates with humeral head changes in osteoarthritis: a radiographic analysis

BACKGROUND

A variety of measurements can be used to assess radiographic osteoarthritic changes of the shoulder. This study aimed to analyze the correlation between the radiographic humeral-sided Samilson and Prieto classification system and 3 different radiographic classifications describing the changes of the glenoid in the coronal plane.

METHODS

The study material included standardized radiographs of 50 patients with idiopathic osteoarthritis before anatomic shoulder replacement. On the basis of radiographic measurements, the cases were evaluated using the Samilson and Prieto grading system, angle β, inclination type, and critical shoulder angle by 2 independent observers.

RESULTS

Classification measurements showed an excellent agreement between observers. Our results showed that the humeral-sided Samilson and Prieto grading system had a statistically significant good correlation with angle β (observer 1, r = 0.74; observer 2, r = 0.77; P < .05) and a statistically significant excellent correlation with the inclination type of the glenoid (observer 1, r  = 0.86; observer 2, r = 0.8; P < .05). A poor correlation to the critical shoulder angle was observed (r = -0.14, r = 0.03; P > .05).

CONCLUSIONS

The grade of humeral-sided osteoarthritis according to Samilson and Prieto correlates with the glenoid-sided osteoarthritic changes of the glenoid in the coronal plane described by the angle β and by the inclination type of the glenoid. Higher glenoid-sided inclination is associated with higher grade of osteoarthritis in primary shoulder osteoarthritis.

The effect of distal tibial rotation during high tibial osteotomy on the contact pressures in the knee and ankle joints

PURPOSE

Intraoperative fracture of the lateral cortex fractures of the tibia is a potential complication of high tibial osteotomy (HTO), which may result in inadequate rotational alignment of the distal tibia. Our aim was to determine how rotational malalignment of the distal tibial segment distal would affect intraarticular contact pressure distribution in the knee and ankle joints.

METHODS

A medial, L-shaped opening-wedge HTO was performed on seven human lower body specimens. A stainless steel device with integrated load cell was used to axially load the leg. Pressure-sensitive sensors were used to measure intraarticular contact pressures. Intraoperative changes in alignment were monitored in real time using computer navigation. Measurements were performed in the native knee alignment, after 10° and 15° of alignment correction and with the distal tibia fixed at 15° of external rotation.

RESULTS

Moderate-to-large alignment changes after medial opening-wedge HTO resulted in a shift in intraarticular contact pressures from the medial compartment of the knee towards the lateral compartment. However, fixation of the distal tibial segment at 15° of external rotation neutralized this intended beneficial effect. In the ankle, external rotation of the distal tibia also caused a reduction in contact pressures and tibiotalar contact area.

CONCLUSION

Malrotation of the distal tibial fragment negates the intended effect of offloading the diseased compartment of the knee, with the contact pressures remaining similar to those of the native knee. Furthermore, malrotation leads to abnormal ankle contact pressures. Care should be taken to ensure appropriate rotational alignment of the distal tibial segment during intraoperative fixation of HTO procedures.

The lasso-loop, lasso-mattress and simple-cinch stitch for arthroscopic rotator cuff repair: are there biomechanical differences?

PURPOSE

Various stitching techniques have been described to facilitate arthroscopic repair of rotator cuff tears. The aim of the present study was to compare the biomechanical properties of the lasso-loop, lasso-mattress and simple-cinch stitch for rotator cuff repair.

METHODS

Twelve infraspinatus tendons were harvested from sheep and split in half. The tendons were randomized into three different stitch configuration groups for biomechanical testing: lasso-loop, lasso-mattress and simple-cinch stitch. Each specimen was first cyclically loaded on a universal materials testing machine under force control from 5 to 30 N at 0.25 Hz for twenty cycles. Then, each specimen was loaded to failure under displacement control at a rate of 1 mm/s. Cyclic elongation, peak-to-peak displacement and ultimate tensile load were reported as mean ± standard error and compared using one way analysis of variance. The type of failure was recorded.

RESULTS

No differences in cyclic elongation (1.31 ± 0.09 mm for the simple-cinch vs. 1.49 ± 0.07 mm for the lasso-mattress vs. 1.61 ± 0.09 mm for the lasso-loop stitch, p = 0.063) or peak-to-peak displacement (0.58 ± 0.04 mm for the simple-cinch, 0.50 ± 0.03 mm for the lasso-mattress and 0.62 ± 0.06 mm for the lasso-loop stitch, p = 0.141) were seen between all tested stitch configurations. In the load-to-failure test, the simple cinch stitch (149.38 ± 11.89 N) and the lasso-mattress (149.38 ± 10.33 N) stitch demonstrated significantly higher ultimate load than the lasso-loop stitch (65.88 ± 4.75 N, p < 0.001). All stitch configurations failed with suture pull out.

CONCLUSIONS

The lasso-mattress and the simple-cinch stitch showed similar biomechanical properties with significant higher tensile loads needed for failure than the lasso-loop stitch.

Arthroscopically Assisted Acromioclavicular and Coracoclavicular Ligament Reconstruction for Chronic Acromioclavicular Joint Instability

Acromioclavicular (AC) joint injuries are common injuries, especially in the young and active, male population. AC joint injuries account for 12% of all injuries of the shoulder girdle in the overall population. Although conservative treatment is recommended for Rockwood type I and type II injuries, there is controversial debate about optimal treatment for type III injuries. High-grade injuries are typically treated operatively to avoid painful sequelae. A vast number of different surgical methods have been described over the past few decades. Recent advances in arthroscopic surgery have enabled the shoulder surgeon to treat acute and chronic AC lesions arthroscopically assisted. Clinical studies have already shown good and reliable results. Although surgeons agree that a biological augmentation is required to minimize the risk of recurrent instability in chronic cases, a gold standard still needs to be defined. We present an arthroscopically assisted biological augmentation technique to reconstruct the AC and coracoclavicular ligaments, protected by a button-suture tape construct for chronic AC joint instability. The presented arthroscopic biological augmentation technique uses less and/or smaller drill holes in the clavicle and coracoid than previously described, thus reducing weakening of the bony structures. At the same time it enhances both horizontal and vertical stability.

Arthroscopic Debridement for Irreparable Rotator Cuff Tears

Background:

Arthroscopic debridement represents a salvage procedure for irreparable rotator cuff tears. It is important to accurately diagnose the patient for irreparable rotator cuff tears. The diagnosis and the therapeutic options must be explained to the patient. It is mandatory that the patient understands the primary goal of the arthroscopic debridement being reduction of pain, not improving strength or function.

Methods:

The procedure consists of 7 distinct steps to debride the soft tissues and alleviate pain.

Results:

Even though there is a lack of evidence that this procedure is superior to other therapeutic options, it has shown good results in patients with the main complaint of pain.

Conclusion:

The results reported in some studies should, however, be interpreted with caution, taking into consideration the substantial structural damage in irreparable defects.

Anatomic stemless shoulder arthroplasty and related outcomes: a systematic review

BACKGROUND

The latest generation of shoulder arthroplasty includes canal-sparing respectively stemless designs that have been developed to allow restoration of the glenohumeral center of rotation independently from the shaft, and to avoid stem-related complications. The stemless prosthesis design has also recently been introduced for use in reverse arthroplasty systems.

METHODS

We systematically reviewed the literature for studies of currently available canal-sparing respectively stemless shoulder arthroplasty systems. From the identified series, we recorded the indications, outcome measures, and humeral-sided complications.

RESULTS

We identified 11 studies of canal-sparing respectively stemless anatomic shoulder arthroplasty implants, published between 2010 and 2016. These studies included 929 cases, and had a mean follow-up of 26 months (range, 6 to 72 months). The rates of humeral component-related complications ranged between 0 and 7.9 %. The studies reported only a few isolated cases of complications of the humeral component. Some arthroplasty systems are associated with radiological changes, but without any clinical relevance.

CONCLUSIONS

All of the published studies of canal-sparing respectively stemless shoulder arthroplasty reported promising clinical and radiological outcomes in short to midterm follow-up. Long-term studies are needed to demonstrate the long-term value of these kind of implants.

Biomechanical evaluation of the simple cinch stitch for arthroscopic rotator cuff repair

BACKGROUND

The tissue-suture interface is described as the most vulnerable and susceptible area in the muscle-tendon-bone construction of arthroscopic rotator cuff repair. Various stitching techniques have been described to enhance the strength, fixation and stability of the repair, but technical and biomechanical challenges remain. Purpose was to examine the biomechanical properties of the simple cinch stitch in comparison to other stitches commonly used for rotator cuff repair.

METHODS

Infraspinatus tendons were harvested from sheep and split in half. The tendons were randomized into five different stitch configuration groups for biomechanical testing: simple stitch; horizontal stitch; FiberChain®; simple cinch stitch; and modified Mason-Allen stitch. Each specimen was first cyclically loaded on a universal materials testing machine under force control from 5 to 30N at 0.25Hz for twenty cycles. Then, each specimen was loaded to failure under displacement control at a rate of 1mm/s. Cyclic elongation, peak-to-peak displacement and ultimate tensile load were measured. The type of failure was recorded.

FINDINGS

No differences in cyclic elongation or peak-to-peak displacement were seen between stitch configurations. In the load-to-failure test, the simple cinch stitch demonstrated significantly higher ultimate load than the simple and the horizontal stitch configurations. The comparison to the FiberChain® Suture revealed no statistical significant differences. The FiberChain® Suture demonstrated significantly higher ultimate load than the simple stitch. No statistical significance could be demonstrated in comparison to the horizontal stitch or the simple cinch stitch. The ultimate tensile load of the modified Mason-Allen stitch was significantly higher than that of the other stitch configurations.

INTERPRETATION

The simple cinch stitch has an ultimate tensile load comparable to the FiberChain® suture and is superior to the simple stitch and the horizontal stitch. The major advantage of the simple cinch technique is that it is possible to perform the stitch entirely arthroscopically, without the need to perforate the tissue a second time or to use special suture materials.

STUDY DESIGN

Controlled laboratory study.

[Limb salvage versus amputation after severe lower extremity injury : Cases from clinical practice]

Following severe lower extremity injury, the potential outcome of a salvage procedure might often be questionable. Objective criteria should help in decision-making. From the clinical practice of a level I trauma center, we demonstrate three case reports and approaches following severe lower extremity injury.

The Anatomic Basis for the Arthroscopic Latarjet Procedure: A Cadaveric Study

BACKGROUND

The Latarjet technique is a reliable treatment option for recurrent anterior shoulder instability. However, the complication rate has been reported to be as high as 30%, with 1.6% of patients suffering a nerve injury. The all-arthroscopic Latarjet procedure has been gaining popularity, even as it has introduced its own challenges. Given that the surgeon is not able to palpate the nerves, their localization and protection can be difficult. Additionally, the use of different instruments can lead to distinct nerve injury mechanisms.

PURPOSE

To describe the anatomic trajectory of the musculocutaneous, axillary, and suprascapular nerves in relation to the arthroscopic Latarjet approach. Using this information, guidance is provided for reducing nerve injuries during instrumentation and screw insertion.

STUDY DESIGN

Descriptive laboratory study.

METHODS

A total of 50 cadaveric shoulders from 25 whole-body specimens were examined. The specimens were placed in the beach-chair position, and the deltopectoral and dorsal approaches were used to expose the relevant structures. A subscapularis muscle split was performed between the inferior and middle thirds of the tendon. Digital caliper measurements were taken between various points of the trajectories of the nerves and surrounding anatomic landmarks. The location of the nerves relative to the split was recorded.

RESULTS

The musculocutaneous nerve lay within the split in 66% of the shoulders (n = 33); it was medial to the split in 28% (n = 14); it was found lateral to split in 2% (n = 1); and it was not identified in 4% of shoulders (n = 2). The mean length of the axillary nerve was 4.0 cm (95% CI, 3.7-4.2) from the exit of the plexus to the quadrangular space. The axillary nerve was found to be within the split in 50% of the shoulders (n = 25) and medial to the split in the remaining 50% (n = 25). The suprascapular nerve at the level of the supraspinatous fossa passed 3.3 cm (95% CI, 3.1-3.5) medial to the superior rim of the posterior glenoid. The nerve curves around the root of the spine at the spinoglenoid notch level, approximating the glenoid rim to a distance of 2.1 cm (95% CI, 2.0-2.2). Finally, the nerve runs medially again before branching out into smaller fibers to innervate the infraspinatus muscle at a distance of 2.9 cm (95% CI, 2.7-3.1) from the inferior glenoid rim. Based on these findings, there is an approximately 2 cm-wide safe zone from the edge of the glenoid rim for the insertion of graft-fixing screws.

CONCLUSION

When performing a subscapularis split in the arthroscopic Latarjet procedure, the risk of injuries to the musculocutaneous and axillary nerves could be reduced by aiming the switching stick inserted through the posterior portal toward the lateral edge of the intended location of the split. Injuries to the suprascapular nerve could be prevented by aiming the graft-fixing screws laterally toward the edge of the glenoid rim.

CLINICAL RELEVANCE

This study clarifies the location of the nerves relevant to the arthroscopic Latarjet technique and provides anatomic information that could help the surgeon reduce the risk of injuries to the musculocutaneous, axillary, and suprascapular nerves.

Biomechanical comparison of two surgical techniques for press-fit reconstruction of the posterolateral complex of the knee

BACKGROUND

To date, various surgical techniques to treat posterolateral knee instability have been described. Recent studies recommended an anatomical and isometric reconstruction of the posterolateral corner addressing the key structures, such as lateral collateral ligament (LCL), popliteus tendon (POP) and popliteofibular ligament (PFL). Two clinical established autologous respective local reconstruction methods of the posterolateral complex were tested for knot-bone cylinder press-fit fixation to assess efficacy of each reconstruction technique in comparison to the intact knee.

NULL HYPOTHESIS

The knot-bone cylinder press-fit fixation for both anatomic and isometric reconstruction techniques of the posterolateral complex shows equal biomechanical stability as the intact posterolateral knee structures.

STUDY DESIGN

This was a controlled laboratory study.

METHODS

Two surgical techniques (Larson: fibula-based semitendinosus autograft for LCL and PFL reconstruction/Kawano: biceps femoris and iliotibial tract autograft for LCL, PFL and POP reconstruction) with press-fit fixation were used for restoration of posterolateral knee stability. Seven cadaveric knees (66 ± 3.4 years) were tested under three conditions: intact knee, sectioned state and reconstructed knee for each surgical technique. Biomechanical stress tests were performed for every state at 30° and 90° knee flexion for anterior-posterior translation (60 N), internal-external and varus-valgus rotation (5 Nm) at 0°, 30° and 90° using a kinemator (Kuka robot).

RESULTS

At 30° and 90° knee flexion, no significant differences between the four knee states were registered for anterior-posterior translation loading. Internal-external and varus-valgus rotational loading showed significantly higher instability for the sectioned state than for the intact or reconstructed posterolateral structures (p < 0.05). There were no significant differences between the intact and reconstructed knee states for internal-external rotation, varus-valgus rotation and anterior-posterior translation at any flexion angles (p > 0.05). Comparing both reconstruction techniques, significant higher varus-/valgus stability was registered for the fibula-based Larson technique at 90° knee flexion (p < 0.05).

CONCLUSIONS

Both PLC reconstructions showed equal biomechanical stability as the intact posterolateral knee structures when using knot-bone cylinder press-fit fixation. We registered restoration of the rotational and varus-valgus stability with both surgical techniques. The anterior-posterior translational stability was not influenced significantly. The Larson technique showed significant higher varus/valgus stability in 90° flexion. The latter is easier to perform and takes half the preparation time, but needs grafting of the semitendinosus tendon. The Kawano reconstruction technique is an interesting alternative in cases of missing autografts.

Nail-medullary canal ratio affects mechanical axis deviation during femoral lengthening with an intramedullary distractor

INTRODUCTION

Callus distraction of the femur using an intramedullary distractor has several advantages over the use of external fixators. However, difficulty in controlling the mechanical axis during lengthening may cause deformities and knee osteoarthritis. Purpose of the study is to answer the following questions: (1) is lengthening with an intramedullary device associated with a medial or lateral shift of the mechanical axis? (2) Which factors are associated with varisation/valgisation of the mechanical axis during lengthening?

MATERIALS AND METHODS

We analysed pre-treatment and post-treatment radiographs from 20 patients who underwent unilateral femoral-lengthening procedures using intramedullary distractors. Patients with acute correction of pre-existing deformities or combined ipsilateral femoral and tibial lengthening were excluded. Mechanical axis deviations, osteotomy level, and nail-medullary canal ratio were recorded.

RESULTS

Compared to the preoperative axis, the mechanical axis shifted medially in 7 patients (varisation group) and laterally in 13 patients (valgisation group). The groups did not significantly differ regarding preoperative leg length discrepancy (LLD), mechanical axis alignment, LLD-cause and implants used. The nail-medullary canal ratio significantly differed between groups (p<0.001), being <85% in the varisation group and >85% in the valgisation group. The distance between the lesser trochanter and the osteotomy site was significantly longer in the valgisation group (58.9±16.3mm, middle third of the femur) compared to the varisation group (40.6±11.4mm, proximal third of the femur; p=0.02).

CONCLUSION

The nail-medullary canal ratio should be considered during preoperative planning. To avoid a varisation effect-for example, in cases with pre-existing varus alignment-it would be advisable to perform an osteotomy at the middle third of the femur with implantation of a nail that fully covers the medullary canal at the osteotomy site.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.