Gian M. Salzmann

The Anatomic Reconstruction of Acromioclavicular Joint Dislocations Using 2 TightRope Devices A Biomechanical Study

Background For the reconstruction of acromioclavicular (AC) joint separation, several operative procedures have been described; however, the anatomic reconstruction of both coracoclavicular ligaments has rarely been reported. Purpose The aim of this biomechanical study is to describe a new procedure for anatomic reconstruction of the AC joint. Study Design Controlled laboratory study. Materials and Methods Forty fresh-frozen cadaveric shoulders were tested. Cyclic loading and a load-to-failure protocol was performed in vertical (native, n = 10; reconstructed, n = 10) and anterior directions (native, n = 10; reconstructed, n = 10) on 20 AC joints and repeated after anatomic reconstruction. Reconstruction of conoid and trapezoid ligaments was achieved by 2 TightRope devices (Arthrex, Naples, Florida). Dynamic, cyclic, and static loading until failure in vertical (n = 5) and horizontal (n = 5) directions were tested in native as well as reconstructed joints in a standardized setting. Results The native coracoclavicular ligaments in static load for vertical force measured 598 N (range, 409–687), elongation 10 mm (range, 6–14), and stiffness 99 N/mm (range, 67–130); static load for anterior force was 338 N (range, 186–561), elongation 4 mm (range, 3–7), and stiffness 140 N/mm (range, 70–210). The mean maximum static load until failure in reconstruction for vertical force was 982 N (range, 584–1330) (P = .001), elongation 4 mm (range, 3–6) (P < .001), and stiffness 80 N/mm (range, 66.6–105) (P = .091); and for anterior static force 627 N (range, 364–973) (P < .001), elongation 6.5 mm (range, 4–10) (P = .023), and stiffness 78 N/mm (range, 46–120) (P = .009). During dynamic testing of the native coracoclavicular ligaments, the mean amount of repetitions (100 repetitions per stage, stage 0–100 N, 100–200 N, 200–300 N, etc, and a frequency of 1.5 Hz) in native vertical direction was 593 repetitions (range, 426–683) and an average of 552 N (range, 452–683) load until failure. In vertical reconstructed testing, there were 742 repetitions (range, 488–893) (P = .222; with a load until failure of 768 N (range, 486–900) (P = .095). In the anterior direction load, the native ligament failed after an average of 365 repetitions (range, 330–475) and an average load of 360 N (range, 307–411), while reconstructed joints ended in 549 repetitions (range, 498–566) (P = .008J with a load until failure of 547 N (range, 490–585) (P = .008). In all testing procedures, a preload of 5 N was performed. Conclusion The anatomic reconstruction of the AC joint using TightRope is a stable and functional anatomic reconstruction procedure. The reconstruction technique led to favorable in vitro results with equal or even higher forces than native ligaments. Clinical Relevance Through anatomic repair, stable function of the AC joint can be achieved in an anatomic manner.

Arthroscopically Assisted 2-Bundle Anatomical Reduction of Acute Acromioclavicular Joint Separations

Background: To achieve reduction of an acute acromioclavicular (AC) joint separation, novel procedures aim to provide stability and function by restoring the coracoclavicular anatomy. Hypothesis: Anatomical reconstruction for acute AC joint disruption using 2 flip-button devices results in satisfactory clinical function and provides a stable fixation. Study Design: Case series; Level of evidence, 4. Methods: The outcome of 23 consecutive patients (21 men, 2 women; mean age, 37.5 ± 10.2 years; range, 21-59 years) who underwent anatomical reduction for an acute AC joint dislocation using 2 flip-button devices, each separately replacing 1 coracoclavicular ligament, was evaluated clinically and radiographically preoperatively and 6, 12, and 24 months postoperatively. The evaluation included a visual analog scale for pain, the Constant score, the simple shoulder test, and the Short Form-36. An additional 7 patients had similar surgery during the same period, but 4 were lost to follow-up, 2 required surgical revision, and 1 developed postoperative infection. Results: There were 3 Rockwood type III, 3 type IV, and 17 type V separations. Mean follow-up was 30.6 ± 5.4 months (range, 24-40 months). The visual analog scale and Constant score showed significant improvements from preoperative 4.5 ± 1.9 (range, 1-7) and 34.3 ± 6.9 (range, 22-44) to postoperative 0.25 ± 0.5 (range, 0-1) and 94.3 ± 3.2 (range, 88-98) at 24 months, respectively. Postoperative radiographic AC joint alignment was unsatisfactory in 8 cases, either in the coronal, axillary, or both planes, with no different clinical outcome when compared with the remaining patients. Conclusion: Immediate anatomical reduction of an acute AC separation with flip-button devices provides satisfactory clinical results at intermediate-term follow-up. This technique should be performed by an experienced arthroscopist; tunnel and button placement are of utmost importance to avoid postoperative failure or loss of reduction.

Sporting Activity after High Tibial Osteotomy for the Treatment of Medial Compartment Knee Osteoarthritis

Background Isolated varus osteoarthritis of the knee is a common problem in patients engaged in sports and recreational activities. Hypothesis Patients will be able to resume sporting activity after high tibial osteotomy. Study Design Case series; Level of evidence, 4. Methods A total of 65 patients were surveyed by postal questionnaires to determine their sporting and recreational activities at an average of 36 ± 8.1 months (range, 14-84) after high tibial osteotomy for the treatment of medial compartment knee osteoarthritis. The clinical evaluation included the Lysholm score, the Tegner activity scale, the Activity Rating Scale, and a visual analog scale for pain. Results At the time of survey, 90.9% of patients were engaged in sports and recreational activities, compared with 87.9% before surgery (P = .182). The number of different sporting activities declined from 3.5 preoperatively to 3.0 after surgery (P = .178). The sports frequency per week (2.1 sessions) and the activity duration per week (4.1 hours) did not significantly change from preoperative to postoperative (2.3, P = .211; and 4.2 hours, P = .709, respectively). The Lysholm score (42.4) and the visual analog scale (6.9) illustrated significant improvements (69.6, P = .001; and 2.9, P < .001, respectively). No patient returned to competitive sports after surgery, and declines were noted in the Tegner (4.9 ± 2.3 to 4.3 ± 1.5, P < .05) and Activity Rating Scale (5.7 ± 5.2 to 3.3 ± 4.6, P = .001) scores. After surgery, many patients continued to engage in high-level activities such as downhill skiing or mountain biking. Conclusion High tibial osteotomy for the treatment of medial compartment knee osteoarthritis in the active patient demonstrated favorable clinical results and allowed patients to return to sports and recreational activities similar to the preoperative level.

The Coracoidal Insertion of the Coracoclavicular Ligaments An Anatomic Study

Background Current surgical procedures restoring a dislocated acromioclavicular joint aim to perform an anatomically correct and biomechanically stable reconstruction. However, the coracoidal insertions for the coracoclavicular ligaments have not yet been defined. Purpose The objective was to evaluate dimension and orientation of the coracoclavicular footprints with respect to bony landmarks for use in anatomic reconstruction of the coracoclavicular ligament complex. Study Design Descriptive laboratory study. Methods Twenty-three (17 female, 6 male) fresh-frozen cadaveric human shoulders were dissected, and the coracoclavicular ligaments including the coracoid and the lateral clavicle were exposed. After measurement of bony coracoidal dimensions, the ligaments were dissected and the insertion sites as well as the footprint centers were identified and marked. Each coracoclavicular insertion dimension and its distance to the bony landmarks was recorded. Sex-related differences were calculated. Results The mean total coracoidal length was 43.1 ± 2.2 mm. The distance from the tip of the coracoid to the precipice, the point at which the undersurface of the coracoid changes from a horizontal to a vertical direction, measured 20.3 ± 2.6 mm. The mean distance from the conoidal center to the medial coracoidal boarder and to the precipice was 1.7 ± 0.7 mm and 16.4 ± 2.4 mm, respectively. The mean distance from the trapezoidal center to the medial border and to the precipice was 8.7 ± 3 mm and 10.9 ± 2.4 mm, respectively. The mean distance between the footprint centers was 10.1 ± 4.2 mm. Conclusion Reproducible dimensions and orientation of the coracoclavicular footprints are given. Clinical Relevance Coracoidal anatomic landmarks can be used intraoperatively for an anatomic reconstruction of the coracoclavicular ligaments.

Arthroscopically Assisted 2-Bundle Anatomic Reduction of Acute Acromioclavicular Joint Separations 58-Month Findings

Background: Currently, no clinical midterm results have been reported on arthroscopically assisted reduction of the acutely dislocated acromioclavicular (AC) joint using suture-button devices for fixation. Hypothesis: Athroscopically assisted reduction of the acutely dislocated AC joint yields satisfactory clinical outcomes without loss of reduction, clavicle migration, or AC joint degeneration at midterm follow-up evaluation. Study Design: Case series; Level of evidence, 4. Methods: The clinical and radiographic outcomes of 23 of 30 consecutive patients (21 men, 2 women) who underwent anatomic reduction for acute AC joint dislocation using 2 suture-button devices between 2006 and 2007 were reviewed. Radiographic evaluation was performed by measurement of coracoclavicular (CC) distance and AC displacement. Clinical evaluation included a visual analog scale (VAS) for pain, the Constant score, the simple shoulder test, and the Short Form–36. Previously, this same patient collective was reviewed after 2 years of follow-up using similar methods. Results: All 23 patients were available for midterm follow-up examination 58 months postoperatively. There were 3 Rockwood type III, 3 type IV, and 17 type V acromioclavicular joint separations. Mean ± SD follow-up was 58 ± 5.6 months (range, 51-67 months). Most patients (96%) remained very satisfied or satisfied with the procedure outcome. The VAS and Constant score improved significantly when compared with baseline (0.3 ± 0.6 and 91.5 ± 4.7 at 58 months postoperatively vs 4.5 ± 1.9 and 34.5 ± 6.9 at baseline) and remained essentially unchanged when compared with the 2-year outcome scores (0.3 ± 0.6 and 91.5 ± 4.7 at 58 months postoperatively vs 0.25 ± 0.5 and 94.3 ± 3.2 at 2 years). Radiographs showed 8 radiographic failures (undercorrection, posterior displacement, or both) and 4 additional overcorrections of the CC distance. When comparing with 24-month data, 17 of 20 radiographs remained unchanged; 1 case of previous overcorrection drifted into normal AC alignment and 2 cases increased in posterior subluxation of the clavicle. Conclusion: Arthroscopically assisted reduction of the acutely dislocated AC joint provides satisfactory clinical results 58 months after surgery. Compared with the baseline, all patients improved significantly. Two of 23 patients revealed an increased posterior dislocation compared with evaluation 24 months after surgery. No further migration of the clavicle or AC joint degeneration was observed.

Long-term Outcomes After First-Generation Autologous Chondrocyte Implantation for Cartilage Defects of the Knee

Background: Autologous chondrocyte implantation (ACI) represents an established surgical therapy for large cartilage defects of the knee joint. Although various studies report satisfying midterm results, little is known about long-term outcomes. Purpose: To evaluate long-term clinical and magnetic resonance imaging (MRI) outcomes after ACI. Study Design: Case series; Level of evidence, 4. Methods: Between January 1997 and June 2001, a total of 86 patients were treated with ACI for isolated cartilage defects of the knee. The mean patient age at the time of surgery was 33.3 ± 10.2 years, and the mean defect size was 6.5 ± 4.0 cm2. Thirty-four defects were located on the medial femoral condyle and 13 on the lateral femoral condyle, while 6 patients were treated for cartilage defects of the trochlear groove and 17 for patellar lesions. At a mean follow-up of 10.9 ± 1.1 years, 70 patients (follow-up rate, 82%) treated for 82 full-thickness cartilage defects of the knee were available for an evaluation of knee function using standard instruments, while 59 of these patients were additionally evaluated by 1.5-T MRI to quantify the magnetic resonance observation of cartilage repair tissue (MOCART) score. Clinical function at follow-up was assessed by means of the Lysholm score, the International Knee Documentation Committee (IKDC) score, and the Knee injury and Osteoarthritis Outcome Score (KOOS). Patient activity was assessed by the Tegner score. In addition, pain on a visual analog scale (VAS) and patient satisfaction were evaluated separately. Results: At follow-up, 77% reported being “satisfied” or “very satisfied.” The mean IKDC score at follow-up was 74.0 ± 17.3. The mean Lysholm score improved from 42.0 ± 22.5 before surgery to 71.0 ± 17.4 at follow-up (P < .01). The mean pain score on the VAS decreased from 7.2 ± 1.9 preoperatively to 2.1 ± 2.1 postoperatively. The mean MOCART score was 44.9 ± 23.6. Defect-associated bone marrow edema was found in 78% of the cases. Nevertheless, no correlation between the MOCART score and clinical outcome (IKDC score) could be found (Pearson coefficient, r = 0.173). Conclusion: First-generation ACI leads to satisfying clinical results in terms of patient satisfaction, reduction of pain, and improvement in knee function. Nevertheless, full restoration of knee function cannot be achieved. Although MRI reveals lesions in the majority of the cases and the overall MOCART score seems moderate, this could not be correlated with long-term clinical outcomes.

Clinical Outcome of Autologous Chondrocyte Implantation for Failed Microfracture Treatment of Full-Thickness Cartilage Defects of the Knee Joint

Background: Although various factors have been identified that influence outcome after autologous chondrocyte implantation (ACI), the relevance of prior treatment of the cartilage defect and its effect concerning the outcome of second-line ACI have not been evaluated to a full extent. Hypothesis: Autologous chondrocyte implantation used as a second-line treatment after failed arthroscopic microfracturing is associated with a higher failure rate and inferior clinical results compared with ACI as a first-line treatment. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 28 patients with isolated cartilage defects at the knee joint were treated with ACI after microfracture as a first-line treatment had failed (failure defined as the necessity of reintervention). These patients were assigned to group A and compared with a matched-pair cohort of patients of identical age, defect size, and defect location (group B) in which ACI was used as a first-line treatment. Failure rates in both groups were assessed. Postoperative knee status was evaluated with the International Knee Documentation Committee (IKDC) score and Knee injury and Osteoarthritis Outcome Score (KOOS), and sporting activity was assessed by use of the Activity Rating Scale. Mean follow-up times were 48.0 months (range, 15.1-75.1 months) in group A and 41.4 months (range, 15.4-83.6 months) in group B. Differences between groups A and B were analyzed by Student t test. Results: Group A had significantly greater failure rates (7 of 28 patients) in comparison with group B (1 of 28 patients; P = .0241). Mean (SD) postoperative IKDC scores revealed 58.4 (22.4) points in group A with a trend toward higher score results (69.0 [19.1] points) for patients in group B (P = .0583). Significantly different results were obtained for KOOS pain and activity of daily living subscales, whereas the remaining KOOS subscales did not show significant differences. Despite the significantly higher failure rate observed in group A, those patients did not participate in fewer activities or perform physical activity less frequently or at a lower intensity. Conclusion: Autologous chondrocyte implantation after failed microfracturing appears to be associated with a significantly higher failure rate and inferior clinical outcome when compared with ACI as a first-line treatment.

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.

Autologous Chondrocyte Implantation for Treatment of Cartilage Defects of the Knee: What Predicts the Need for Reintervention?

Background: Autologous chondrocyte implantation (ACI) is a well-established treatment option for isolated cartilage defects of the knee joint, providing satisfying outcome. However, cases of treatment failure with the need for surgical reintervention are reported; typical patient’s individual and environmental risk factors have previously not been described. Hypothesis: The need for reintervention after ACI is associated with specific preoperative detectable individual risk factors. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 413 patients following ACI (first, second, and third generation) were filtered for those who required revision surgery during their follow-up time (2-11.8 years). Factors were analyzed that might have significant effects on increased revision rate. Using preoperatively collected data, all patients were grouped according to 12 standard prognostic factors. Apart from odds ratio and Pearson χ2 test, statistical analysis of risk factors was performed with multivariate binary logistic regression models and Cox regression, the method of choice for survival time data. Results: After a follow-up of 4.4 ± 0.9 years (limited to 5 years), a total of 88 patients (21.3%) had undergone surgical revision. The time to revision surgery was 1.8 ± 1.1 years. Four prognostic factors associated with a significantly higher risk for reintervention were detected: (1) female gender (Cox survival fit: P = .033), (2) previous surgeries of the affected joint (P = .002), (3) previous bone marrow stimulation (P = .041), and (4) periosteum patch–covered ACI (P = .028). An influence of patient age, body mass index (BMI), defect number, defect size, lesion origin, lesion location, parallel treatment, or smoking on the risk for reintervention could not be observed. Conclusion: The study identifies clear facts that significantly increase the risk of revision surgery. These facts can be easily obtained preoperatively and may be taken into consideration when indicating ACI.

Autologous chondrocyte implantation for treatment of focal cartilage defects in patients age 40 years and older: A matched-pair analysis with 2-year follow-up.

Background Autologous chondrocyte implantation (ACI) is an accepted surgical treatment in patients with isolated cartilage defects of the knee. Age has been considered as a limiting factor and the technique has not been recommended in patients older than 40 to 50 years. Nevertheless, some more recent studies report satisfying clinical results in middle-aged patients. Hypothesis Analogous to the microfracture technique, age over 40 years is associated with inferior clinical outcome after ACI. Study Design Cohort study; Level of evidence, 2. Methods Thirty-seven patients with an average age of 47.8 years (group 1) were matched with 37 patients with an average age of 31 years (group 2). Both groups underwent ACI for treatment of isolated cartilage defects of the knee. All patients were enrolled prospectively and followed for a period of 24 months using International Knee Documentation Committee (IKDC), Lysholm scale, Cincinnati sports scale, and Tegner activity evaluation instruments. Results Statistical analysis revealed a significant increase in function after ACI in both groups as early as 6 months after surgery until the end of the study period. There was only a slight tendency for better clinical outcome in younger patients (IKDC at 24 months: group 1, 72.2 ± 15.8 [standard deviation]; group 2: 76.1 ± 14.1; P = .261; Lysholm at 24 months: group 1: 80.42 ± 15.37; group 2: 80.65 ± 12.01), no statistical significant differences were found between patients of group 1 and group 2 at any of the time points investigated. Conclusion In contrast to other cartilage repair techniques, patients 40 years and older do not have an inferior outcome up to 24 months after ACI for isolated cartilage defects when compared with younger patients.