Atrophy patterns in isolated subscapularis lesions.

BACKGROUND: While supraspinatus atrophy can be described according to the system of Zanetti or Thomazeau there is still a lack of characterization of isolated subscapularis muscle atrophy. The aim of this study was to describe patterns of muscle atrophy following repair of isolated subscapularis (SSC) tendon. METHODS: Forty-nine control shoulder MRI scans, without rotator cuff pathology, atrophy or fatty infiltration, were prospectively evaluated and subscapularis diameters as well as cross sectional areas (complete and upper half) were assessed in a standardized oblique sagittal plane. Calculation of the ratio between the upper half of the cross sectional area (CSA) and the total CSA was performed. Eleven MRI scans of patients with subscapularis atrophy following isolated subscapularis tendon tears were analysed and cross sectional area ratio (upper half /total) determined. To guarantee reliable measurement of the CSA and its ratio, bony landmarks were also defined. All parameters were statistically compared for inter-rater reliability, reproducibility and capacity to quantify subscapularis atrophy. RESULTS: The mean age in the control group was 49.7 years (± 15.0). The mean cross sectional area (CSA) was 2367.0 mm2 (± 741.4) for the complete subscapularis muscle and 1048.2 mm2 (± 313.3) for the upper half, giving a mean ratio of 0.446 (± 0.046). In the subscapularis repair group the mean age was 56.7 years (± 9.3). With a mean cross sectional area of 1554.7 mm2 (± 419.9) for the complete and of 422.9 mm2 (± 173.6) for the upper half of the subscapularis muscle, giving a mean CSA ratio of 0.269 (± 0.065) which was seen to be significantly lower than that of the control group (p < 0.05). CONCLUSION: Analysis of typical atrophy patterns of the subscapularis muscle demonstrates that the CSA ratio represents a reliable and reproducible assessment tool in quantifying subscapularis atrophy. We propose the classification of subscapularis atrophy as Stage I (mild atrophy) in case of reduction of the cross sectional area ratio < 0.4, Stage II (moderate atrophy) in case of < 0.35 and Stage III (severe atrophy) if < 0.3.

Patients' expectations of shoulder instability repair.

PURPOSE: To analyze and compare patient expectations of primary and revision shoulder stabilization and to assess the factors associated with patients' expectations. METHODS: Pre-operative patient expectations after shoulder instability repair were prospectively assessed using a self-designed questionnaire. The survey included questions on the expected level and type of return to sports, instability, pain, risk of osteoarthritis, and overall shoulder condition. RESULTS: One-hundred and forty-five patients (99 primary; 46 revision repair) were included. A return to sport at the same level with slight to no restrictions was expected in 95%, a return to high-risk activities in 34%, to moderate in 58%, and to low-risk activities in 9%. No pain [instability] independent of the activity level was expected by 71% [79%] and occasional pain [instability] during contact and overhead activities by 25% [19%]. 61% expected to have no risk of glenohumeral osteoarthritis, 37% a slight, and 2% a significant risk. The overall expectation for the post-operative shoulder was indicated to be normal or nearly normal in 99% of patients. The revision group did not differ from the primary repair group in any variable. High pre-operative sport performance was positively correlated with post-operative sport expectations. The number of dislocations, the duration of instability, and the subjective instability level were negatively correlated with return to sport expectations. CONCLUSION: Patient expectations for primary and revision shoulder instability repair are high. Realistic patient expectations regarding the surgical procedure are necessary to avoid low patient satisfaction, especially in pre-operatively highly active and demanding athletes. The surgeon must not solely base the treatment on the pathology and possible risk factors for failure but should also take the individual expectation of the patient into account. LEVEL OF EVIDENCE: III.

Single versus double row suture anchor fixation for greater tuberosity fractures - a biomechanical study.

BACKGROUND: Fractures of the humeral greater tuberosity (GT) are a frequent injury progressively treated with arthroscopic suture anchor repair. Yet, no biomechanical study has been performed comparing fixation strength of arthroscopic single- (SR) vs. double row (DR) fixation. METHODS: Standardized fractures of the greater tuberosity were created in 12 fresh frozen proximal humeri. After random assignation to the SR or DR group the fixed humeri were tested applying cyclic loading to the supraspinatus and infraspinatus tendon. Load to failure and fragment displacement were assessed by means of an electrodynamic material testing machine using an optical tracking system. RESULTS: Load to failure values were higher in the DR group (649 N; ±176) than in the SR group (490 N; ±145) however without statistical significance (p = .12). In greater tuberosity displacement of 3-5 mm surgical treatment is recommended. The fixing constructs in this study did not reach displacement landmarks of 3 or 5 mm before construct failure as shown in previous studies. Thus the applied traction force (N) at 1 mm displacement was analyzed. In the SR group the load at 1 mm displacement was 277 N; ±46 compared to 260 N; ±62 in the DR group (p = .65). CONCLUSION: The results suggest that both techniques are viable options for refixation of greater tuberosity fractures. LEVEL OF EVIDENCE: Laboratory study.

Long-term Results After Arthroscopic Repair of Isolated Subscapularis Tears.

BACKGROUND: Although some reports have presented short- to midterm results after arthroscopic repair of isolated subscapularis (SSC) tendon tears, long-term evaluation is still lacking. HYPOTHESIS: Long-term results after arthroscopic repair of isolated SSC tears are comparable with the functional and radiological short- to midterm outcomes described in the literature. STUDY DESIGN: Case series, Level of evidence, 4. METHODS: This study assessed 17 patients (5 females and 12 males; mean age, 45.6 years) with isolated SSC tears (Fox and Romeo classification types 2-4) who underwent all-arthroscopic suture anchor repair. The mean interval from symptom onset to the time of surgery was 5.3 months in 16 patients (94.1%). One patient (5.9%) was symptomatic for a prolonged period (104 months) before surgery. All patients were assessed with a clinical examination preoperatively. SSC function was investigated using specific clinical tests and common scoring systems, including Constant, American Shoulder and Elbow Surgeons (ASES), Disabilities of the Arm, Shoulder and Hand (DASH), and Simple Shoulder Test (SST) scores. At follow-up, muscular strength was evaluated using an electronic force-measuring plate. Structural integrity of the repair was assessed using magnetic resonance imaging (MRI). RESULTS: At a mean follow-up of 98.4 ± 19.9 months, the mean Constant score improved from 47.8 preoperatively to 74.2 postoperatively ( P = .001). Higher Constant ( P = .010) and ASES ( P = .001) scores were significantly associated with a shorter time from symptom onset to surgery. The size of the SSC lesion did not correlate with any clinical score outcome ( P = .476, .449, .985, and .823 for Constant, ASES, DASH, and SST scores, respectively). Three patients (17.6%) had persistent positive clinical test results (belly-press/lift-off). Compared with the uninjured contralateral side, SSC strength was significantly reduced in the belly-press position ( P = .031), although active internal ( P = .085) and external ( P = .093) rotation was not affected. In 1 patient, a rerupture was detected by MRI. Six patients had cranial SSC atrophy. Overall, 88.2% of patients were "very satisfied" or "satisfied" with their results. CONCLUSION: Arthroscopic repair of isolated SSC tears results in significant clinical improvements and enduring tendon integrity, although SSC strength remains reduced in the long term. Early surgical treatment seems to be a relevant factor allowing good shoulder function.

Results of Arthroscopic Bankart Repair for Anterior-Inferior Shoulder Instability at 13-Year Follow-up.

BACKGROUND: Anterior-inferior shoulder instability is a common injury in young patients, particularly those practicing overhead-throwing sports. Long-term results after open procedures are well studied and evaluated. However, the long-term results after arthroscopic repair and risk factors of recurrence require further assessment. HYPOTHESIS: Arthroscopic Bankart repair results are comparable with those of open repair as described in the literature. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A total of 180 shoulders with anterior-inferior shoulder instability were stabilized arthroscopically, met the inclusion criteria and the patients were able to be contacted at a minimum of 10-year follow-up. Of these patients, 143 agreed to participate in the study. Assessment was performed clinically in 104 patients using the American Shoulder and Elbow Surgeons score, Constant score, American Academy of Orthopaedic Surgeons score, Rowe score, and the Dawson 12-item questionnaire. The Samilson-Prieto score was used to assess degenerative arthropathy in radiographs available for 100 shoulders. Additionally, 15 patients participated through a specific questionnaire and 24 patients through a telephone survey. RESULTS: The overall redislocation rate was 18.18%. Redislocation rates for the different types of fixation devices were as follows: FASTak/Bio-FASTak, 15.1% (17/112); SureTac, 26.3% (5/19); and Panalok, 33.3% (4/12). Concomitant superior labral anterior-posterior repair had no effect on clinical outcome. Redislocation rate was significantly affected by the patient's age and duration of postoperative rehabilitation. Redislocation rate tended to be higher if there had been more than 1 dislocation preoperatively ( P = .098). Severe dislocation arthropathy was observed in 12% of patients, and degenerative changes were significantly correlated with the number of preoperative dislocations, patient age, and number of anchors. The patient satisfaction rate was 92.3%, and return to the preinjury sport level was possible in 49.5%. CONCLUSION: Clinical outcome at a mean follow-up of 13 years after arthroscopic repair of anterior-inferior shoulder instability is comparable with the reported results of open Bankart repair in the literature and allows management of concomitant lesions arthroscopically. Modifiable risk factors of postoperative redislocation and arthropathy must be considered. Stabilization after the first-time dislocation achieves better clinical and radiological outcomes than after multiple dislocations.

A multicenter study to evaluate subscapularis muscle function using 5:30 o'clock portal for antero-inferior shoulder stabilization.

INTRODUCTION: The purpose of this study was to compare the outcome after arthroscopic antero-inferior shoulder stabilization with and without using a 5:30 o'clock portal. MATERIALS AND METHODS: Sixty-two patients [age (mean ± SD), 28.05 ± 8.25 years] with a mean follow-up of 15.23 ± 5.02 months were included in this study. Thirty-one patients underwent arthroscopic antero-inferior shoulder stabilization using the 5:30 o'clock portal in center A (group I) and were compared to 31 matched patients managed with the 3 o'clock portal in center B (group II). Physical examination, standard shoulder scores, ultrasound assessment and subscapularis strength measurement were used to evaluate postoperative shoulder function. RESULTS: Good to excellent results were seen in both groups. No significant differences were seen when comparing ASES, Constant and Rowe Score of both groups. Patients of group II achieved a significant higher score in the SST than patients of group I. (p < 0.05) Patients of group I had a significantly lesser loss of passive external rotation in 0° and 90° of abduction. (p = 0.04; p = 0.056) Ultrasound evaluation and strength measurement showed no significant differences in subscapularis muscle integrity or function neither between the involved and uninvolved shoulder nor between both groups. CONCLUSION: Arthroscopic anterior-inferior shoulder stabilization results in excellent clinical results. When considering portal placement, the deep trans-subscapularis portal allows a more precise suture anchor placement at the inferior glenoid rim and capsular shift with a significant improved external rotation but does not negatively affect the subscapularis function in terms of internal rotation strength or structural integrity. LEVEL OF EVIDENCE: III.

Sporting Activity After Arthroscopic Bankart Repair for Chronic Glenohumeral Instability.

PURPOSE: The purpose of this study was to collect detailed data on postoperative sporting activity after arthroscopic Bankart repair for chronic shoulder instability. METHODS: Of 113 patients who underwent arthroscopic Bankart repair between February 2008 and August 2010, 81 met the inclusion criteria and were surveyed by a specially designed postal sport-specific questionnaire. Of these 81 patients, 66 (82%) were available for evaluation. RESULTS: All previously active patients performed some activity at follow-up. Of 9 patients (56%) who had been inactive, 5 took up new activities postoperatively. Forty-four patients (66%) stated that surgery had (strongly) improved their sporting proficiency. Seventeen patients (26%) reported no impact, and 5 patients (8%) reported a further deterioration compared with preoperatively. The improvement in sporting proficiency was negatively correlated with the preoperative risk level (ρ = 0.42, P < .001), preoperative performance level (ρ = 0.31, P = .012), and preoperative Tegner scale (ρ = 0.36, P = .003), as well as hours of sporting activity per week (ρ = 0.25, P = .042), whereas age showed a positive correlation (ρ = 0.28, P = .023). There was no change in duration, frequency, number of disciplines, Tegner activity scale, risk category, or performance level. CONCLUSIONS: Arthroscopic Bankart repair provides a high rate of return to activity among patients treated for chronic shoulder instability. A number of previously inactive patients returned to activity postoperatively. However, one-third of patients reported no benefit from surgery in terms of sporting activity. The improvement in sporting proficiency was highly dependent on the demands on the shoulder in sports, as well as the age of the patient. Overall, there was no significant increase in duration, frequency, number of disciplines, Tegner activity scale, or performance level between preoperative and follow-up evaluation and no increased return to high-risk activities. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Arthroscopic Suture Anchor Fixation of Bony Bankart Lesions: Clinical Outcome, Magnetic Resonance Imaging Results, and Return to Sports.

PURPOSE: The purpose of this study was to evaluate the outcome, return to sporting activity, and postoperative articular cartilage and bony morphology of shoulders that underwent arthroscopic suture anchor repair of bony Bankart lesions. METHODS: The inclusion criteria for this retrospective study were anterior glenoid rim fractures after traumatic shoulder instability that were treated with arthroscopic suture anchor repair. Patients were surveyed by a questionnaire including sport-specific outcome, Rowe score, Western Ontario Shoulder Instability Index, and Oxford Instability Score. Three-tesla magnetic resonance imaging could be performed in 30 patients to assess osseous integration, glenoid reconstruction, and signs of osteoarthritis. RESULTS: From November 1999 to April 2010, 81 patients underwent an anterior bony Bankart repair in our department (50 arthroscopic suture anchor repairs, 5 arthroscopic screw fixations, and 26 open repairs). The 55 arthroscopic repairs comprised a consecutive cohort of patients treated by a single surgeon. Of the 50 patients in the suture anchor group, 45 (90%) were available for evaluation. At 82 ± 31 months postoperatively, the mean Rowe score was 85.9 ± 20.5 points, the mean Western Ontario Shoulder Instability Index score was 89.4% ± 14.7%, and the mean Oxford Instability Score was 13.6 ± 5.4 points. Compared with the contralateral shoulder, all scores showed a significantly reduced outcome (P < .001, P < .001, and P < .001, respectively). A redislocation occurred in 3 patients (6.6%). Regarding satisfaction, 35 patients (78%) were very satisfied, 9 (20%) were satisfied, and 1 was partly satisfied. Overall, 95% of patients returned to any sporting activity after surgery. The number of sports disciplines (P < .001), duration (P = .005), level (P = .02), and risk category (P = .013) showed a significant reduction compared with the pretrauma condition. However, only 19% of patients reported that shoulder complaints were the reason for the reduction in activity. Nonunion occurred in 16.6%, with a higher frequency in patients with chronic lesions (P = .031). Anatomic reduction was achieved in 72%, the medial step-off in patients with nonanatomic reduction averaged 1.8 ± 0.9 mm, and the remaining glenoid defect size averaged 6.8% ± 7.3%. Full-thickness cartilage defects of the anterior glenoid were detected in 70% of patients. CONCLUSIONS: Arthroscopic suture anchor repair may enable an anatomic reduction of bony Bankart lesions with no or only minimal articular steps and provides successful midterm outcomes concerning clinical scores, recurrence, and patient satisfaction. The return to activity is limited for various, mostly non-shoulder-related causes. Chronic lesions may have an inferior healing potential; therefore early surgical stabilization of acute Bankart fragments is suggested to avoid possible nonunion. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Prevalence of and Risk Factors for Dislocation Arthropathy: Radiological Long-term Outcome of Arthroscopic Bankart Repair in 100 Shoulders at an Average 13-Year Follow-up.

BACKGROUND: Glenohumeral osteoarthritis is a well-documented, long-term complication of open stabilization procedures. However, there is a lack of knowledge about long-term radiographic outcome after arthroscopic Bankart procedures. HYPOTHESIS: Glenohumeral osteoarthritis will develop less frequently in arthroscopic Bankart repair compared with open repairs reported in the literature. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: The inclusion criteria for this study were (1) all-arthroscopic Bankart repair for a (2) symptomatic anteroinferior shoulder instability and (3) a minimum follow-up of 10 years. True anteroposterior and lateral radiographs were obtained to evaluate the prevalence and grade of osteoarthritis according to the Samilson classification. Patients were assessed by the Constant score and examined for passive external rotation deficits. RESULTS: Of 165 shoulders that fulfilled the inclusion criteria, 100 were available for evaluation. The median Constant score at an average±SD 156.2±18.5 months after Bankart repair was 94 (range, 46-100). Twenty-one shoulders (21%) sustained a recurrent dislocation. Overall, 31% of shoulders showed no evidence of glenohumeral osteoarthritis; 41% showed mild, 16% moderate, and 12% severe degenerative changes. Osteoarthritis did not correlate with Constant score results (P=.427). The grade of osteoarthritis was significantly associated with the number of preoperative dislocations (P=.016), age at initial dislocation (P=.005) and at surgery (P=.002), and the number of anchors used (P=.001), whereas time from initial dislocation to surgery (P=.854) and external rotation deficit at 0° and 90° of abduction (P=.104 and .348, respectively) showed no significant correlation. Recurrent dislocation did not affect the presence or grade of osteoarthritis (P=.796 and .665, respectively). CONCLUSION: At an average 13 years after arthroscopic Bankart repair, osteoarthritic changes are a common finding and, overall, are comparable with reports in the literature regarding open procedures as well as nonoperative treatment. The extent of trauma sustained during preoperative dislocations and the age of the patient seem to be more relevant for long-term dislocation arthropathy than the kind of treatment. Accordingly, the study hypothesis must be rejected. Avoiding preoperative dislocations is more important for the prevention of osteoarthritis than short-term treatment. The number of anchors used was found to be a predictor for long-term development of osteoarthritis.

Gross anatomical and dimensional characteristics of the proximal hamstring origin.

PURPOSE: The current study was undertaken to better define the gross anatomical and dimensional characteristics of the proximal hamstring origin. METHODS: Twelve paired whole-lower extremities from six embalmed cadavers were dissected. The gross anatomy of the proximal hamstrings was studied. With the tendons attached to the ischial tuberosity, the width and thickness of each tendon was measured 1 cm distally to their origin, and the distance from the most proximal border of the common origin of the semitendinosus (ST) and long head of the biceps (LB) to their distal junction was assessed. After removal of the hamstring group, the shape, orientation, and dimension of the tendon footprints were determined. RESULTS: One cadaver demonstrated unique anatomy, which was considered as an anatomic variant and was therefore excluded from the study group. The ST and LB had a common origin on the posterolateral aspect of the ischial tuberosity (ST/LB), whereas the semimembranosus (SM) had a separated origin at the anterolateral aspect. The mean distance from the most proximal border of the ST/LB origin to the distal junction was 10.0 ± 1.3 cm. The shape of both footprints was longitudinal-oval, with the longitudinal axes of the SM and ST/LB footprints parallel aligned. Mean tendon width was 3.4 ± 0.5 cm for the common ST/LB complex and 4.2 ± 0.9 cm for the SM (p = 0.009). The corresponding values for tendon thickness were 1.0 ± 0.3 cm (ST/LB) and 0.8 ± 0.2 cm (SM), respectively (n.s.). Mean footprint length was 3.9 ± 0.4 cm for ST/LB and 4.5 ± 0.5 cm for SM (p = 0.002). The corresponding values for footprint height were 1.4 ± 0.5 cm (ST/LB) and 1.2 ± 0.3 cm (SM), respectively (n.s.). CONCLUSION: The ST and LB had a common origin, whereas the SM originated separately. The site of origin of both tendons was the lateral aspect of the ischial tuberosity, with the SM footprint lying directly anterior to the footprint of the ST/LB complex. The footprint of the SM was significantly wider than the footprint of the ST/LB. The reported gross anatomic findings and dimensions may aid surgeons in anchor placement at the anatomical attachment site, thereby facilitating anatomic hamstring repair. In addition, the provided data may improve diagnosis and conservative treatment of proximal hamstring tendinopathy, since detailed knowledge about the normal anatomy is crucial for recognizing tendon abnormalities and for several conservative treatment modalities such as shockwave application or ultrasound-guided injections.

Popliteal entrapment syndrome caused by fibular osteochondroma.

Osteochondromas are the most common tumors of bone. In adolescence, they usually present as a painless growing mass. Femoropopliteal vascular complications associated with an osteochondroma are rare, with most cases involving pseudoaneurysms. This report describes an exceptional case of a popliteal entrapment syndrome caused by a proximal fibular osteochondroma.

Subscapularis function and structural integrity after arthroscopic repair of isolated subscapularis tears.

BACKGROUND: Results of arthroscopic repair of isolated subscapularis tendon tears have not been widely studied. A detailed evaluation of subscapularis function with subscapularis strength quantification has not been performed to date. PURPOSE: To evaluate postoperative subscapularis muscle function and to assess the clinical outcome and structural tendon integrity with postoperative magnetic resonance imaging after arthroscopic repair of isolated subscapularis tears. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: In a prospective study, isolated subscapularis tendon tears in 21 patients were treated with an all-arthroscopic repair. The average age of the study population was 43 years. The mean interval between trauma and surgery was 5.8 months. In 19 patients, a traumatic event caused the onset of symptoms. Subscapularis muscle function was assessed with specific clinical tests and the Constant scoring system. Postoperative subscapularis strength was evaluated with a custom-made electronic force measurement plate. All patients underwent postoperative magnetic resonance imaging to assess structural integrity of the repair. RESULTS: The average duration of follow-up was 27 months. The Constant score increased from 50 points preoperatively to 82 points postoperatively (P < .01). Most positive preoperative lift-off and belly-press tests were reversed by surgery, with a rate of 5 (24%) persistent positive tests after surgery. In operated shoulders, subscapularis strength in the belly-press (65 vs 87 N; P < .05) and the lift-off position (44 vs 68 N; P < .05) was significantly reduced compared with the contralateral shoulder. Magnetic resonance imaging revealed an intact repair in 20 patients. Atrophy of the upper subscapularis muscle portion was present in about one-fourth of the patients and in all patients with a positive postoperative belly-press test. CONCLUSION: Arthroscopic repair of isolated subscapularis tendon tears achieves substantial improvement of shoulder function and a low rerupture rate. Despite excellent clinical results, a significant postoperative subscapularis strength deficit compared with the contralateral shoulder persists that can be quantified with use of the force measurement plate. Atrophy of the upper subscapularis muscle is present in 25% of the patients in the postoperative course.