Arthroscopic Removal of a Polyethylene Glenoid Component in Total Shoulder Arthroplasty

We present a technique for arthroscopic glenoid removal in a case of glenoid loosening after total shoulder arthroplasty (TSA). The presented technique is technically feasible and may be useful if 1-stage surgery with glenoid reimplantation is not indicated. To exclude low-grade infection, the presented technique allows for an intraoperative infection workup such as intraoperative cultures. However, glenoid loosening in TSA is a well-known problem and has been described before. The advantages of the presented technique include minimally invasive surgery, decreased pain, preservation of the subscapularis tendon, and assurance of exclusion of low-grade infection before reimplantation of a new glenoid implant. In this case a 73-year-old patient was treated with a TSA for severe osteoarthritis of the right shoulder in April 2014. Because of persistent anterior shoulder pain postoperatively, radiographic evaluation was performed and showed signs of glenoid loosening 6 months after surgery without any clinical signs of infection. To exclude low-grade infection, arthroscopy of the right shoulder was performed. Arthroscopy showed a totally loosened glenoid component leading to arthroscopic glenoid removal by use of a special forceps

Measurement of meniscofemoral contact pressure after repair of bucket-handle tears with biodegradable implants

INTRODUCTION: Biodegradable implants are frequently used for meniscus repair. Articular cartilage damage has been reported recently after meniscus repair with biodegradable implants. The aim of the study was to investigate the meniscofemoral contact pressure at the posterior horn of the medial and lateral meniscus after repair of bucket-handle lacerations. MATERIALS AND METHODS: Specimens were mounted in a materials testing machine (Bionix 858, MTS) which was equipped with a load cell. The quadriceps tendon was attached to a hydraulic cylinder, and knee motion was controlled via tension of the quadriceps tendon. A piezo-resistive system (Tekscan, Boston, MA, USA) measured the meniscofemoral contact pressure. Five different types of biodegradable implants (Arrow, Dart, Fastener, Stinger and Meniscal Screw) and horizontal suture (no. 2 Ethibond) were tested. The knee was extended from 90 degrees of flexion to 0 degrees under a constant load of 350 N due to adjustment of the tension force of the quadriceps tendon. The femorotibial pressure and contact area were recorded at 0 degree, 30 degrees, 60 degrees and 90 degrees of flexion. RESULTS: The meniscofemoral pressure did not increase after meniscus repair with biodegradable implants or sutures. The meniscofemoral peak pressure at the posterior horn was 1.46+/-1.54 MPa in the medial compartment and 1.08+/-1.17 MPa in the lateral compartment at full knee extension. The meniscofemoral pressure increased significantly in both compartments with knee flexion from 0 degree to 90 degrees. CONCLUSION: Biodegradable implants for meniscus repair do not affect the meniscofemoral pressure. However, there remains a risk of damage to the cartilage when barbed implants are used. If the implant is not entirely advanced into the meniscus, the sharp head or some of the barbs at the column of the implant may come into direct contact with the articular cartilage of the femoral condyle or tibial plateau. The authors presume that in

Planning Results for High Tibial Osteotomies in Degenerative Varus Osteoarthritis Using Standing and Supine Whole Leg Radiographs

Objective In this study, we hypothesized that standing and supine X-rays lead to different preoperative planning results. Methods The present study included 168 pictures from 81 patients who were treated surgically with high tibial osteotomy (HTO) for varus deformity between January 2017 and February 2018. Each patient underwent whole leg X-ray examinations in both standing and supine position. On both images, the following parameters were measured: degree of axis deviation (DAD), mechanical lateral distal femoral angle (mLDFA), mechanical medial proximal tibial angle (mMPTA), width of medial (MJS) and lateral joint space (LJS), and the correction angle (CA). The results were correlated with the patients' age and body mass index (BMI). To analyze intra-observer reliability, the same researcher, blinded to the previous measurements, remeasured all X-rays from 10 patients 8 weeks after the initial measurements were carried out. Results While mLDFA (P = 0.075), mMPTA (P = 0.435), and MJS (P = 0.119) did not show any differences between the two modalities, LJS (P = 0.016) and DAD (P < 0.001) differed significantly, leading to different correction angles (P < 0.001). The mean difference of the CA was 1.7 degrees +/- 2.2 degrees (range, -2.6 degrees to-15.4 degrees). In 14 legs (17%), the standing X-ray led to a correction angle that was at least 3 degrees larger than the calculation revealed in the supine X-ray; in 4 legs (5%), it was at least 5 degrees larger. Increased BMI (r = 0.191, P = 0.088) and older age (r = 0.057 , P = 0.605) did not show relevant correlation with DAD differences. However, more severe varus malalignment in the supine radiograph did correlate moderately with differences of correction angles between supine and weight-bearing radiographs (r = 0.414, P < 0.001). The analysis of the intra-rater reliability revealed mediocre to excellent intercorrelation coefficients between the measurements of the observer. Conclusion The use of supine and standing X-ray images leads to different planning results when performing high tibial osteotomies for varus gonarthrosis. To avoid potential overcorrection, surgeons might consider increased lateral joint spaces on standing radiographs in osteoarthritic knees with varus deviation

Planning results for high tibial osteotomies in degenerative varus osteoarthritis using standing and supine whole leg radiographs

$\bf Objective$ In this study, we hypothesized that standing and supine X‐rays lead to different preoperative planning results. $\bf Methods$ The present study included 168 pictures from 81 patients who were treated surgically with high tibial osteotomy (HTO) for varus deformity between January 2017 and February 2018. Each patient underwent whole leg X‐ray examinations in both standing and supine position. On both images, the following parameters were measured: degree of axis deviation (DAD), mechanical lateral distal femoral angle (mLDFA), mechanical medial proximal tibial angle (mMPTA), width of medial (MJS) and lateral joint space (LJS), and the correction angle (CA). The results were correlated with the patients’ age and body mass index (BMI). To analyze intra‐observer reliability, the same researcher, blinded to the previous measurements, remeasured all X‐rays from 10 patients 8 weeks after the initial measurements were carried out. $\bf Results$ While mLDFA ($\it P$ = 0.075), mMPTA ($\it P$ = 0.435), and MJS ($\it P$ = 0.119) did not show any differences between the two modalities, LJS ($\it P$ = 0.016) and DAD ($\it P$ < 0.001) differed significantly, leading to different correction angles ($\it P$ < 0.001). The mean difference of the CA was 1.7° $\pm$ 2.2° (range, −2.6° to−15.4°). In 14 legs (17%), the standing X‐ray led to a correction angle that was at least 3° larger than the calculation revealed in the supine X‐ray; in 4 legs (5%), it was at least 5° larger. Increased BMI (r = 0.191, $\it P$ = 0.088) and older age ($\it r$ = 0.057 , $\it P$ = 0.605) did not show relevant correlation with DAD differences. However, more severe varus malalignment in the supine radiograph did correlate moderately with differences of correction angles between supine and weight‐bearing radiographs ($\it r$ = 0.414, $\it P$ < 0.001). The analysis of the intra‐rater reliability revealed mediocre to excellent intercorrelation coefficients between the measurements of the observer. $\bf Conclusion$ The use of supine and standing X‐ray images leads to different planning results when performing high tibial osteotomies for varus gonarthrosis. To avoid potential overcorrection, surgeons might consider increased lateral joint spaces on standing radiographs in osteoarthritic knees with varus deviation

A biomechanical comparison of steel screws versus PLLA and magnesium screws for the Latarjet procedure

$\bf Introduction$ The fixation of the coracoid process onto the glenoid is an important step of the Latarjet procedure, and implant-associated complications are a relevant and severe problem. This study compares the fixation strength and failure mode of two biodegradable materials with stainless-steel screws. $\bf Methods$ 24 Fresh-frozen cadaveric scapulae were divided into three groups of equal size and received a coracoid transfer. Cadavers were matched according to their bone mineral density (BMD). In group 1, small-fragment screws made of stainless steel were used. In the second group, magnesium screws were used, and in the third group, screws consisted of polylactic acid (PLLA). A continuously increasing sinusoidal cyclic compression force was applied until failure occurred, which was defined as graft displacement relative to its initial position of more than 5 mm. $\bf Results$ At 5-mm displacement, the axial force values showed a mean of 374 $\pm$ 92 N (range 219–479 N) in group 1 (steel). The force values in group 2 (magnesium) had a mean of 299 $\pm$ 57 N (range 190–357 N). In group 3 (PLLA), failure occurred at 231 $\pm$ 83 N (range 109–355 N). The difference between group 1 (steel) and group 2 (magnesium) was not statistically significant ($\it P$ = 0.212), while the difference between group 1 (steel) and group 3 (PLLA) was significant ($\it P$ = 0.005). $\bf Conclusion$ Stainless-Steel screws showed the highest stability. However, all three screw types showed axial force values of more than 200 N. Stainless steel screws and PLLA screws showed screw cut-out as the most common failure mode, while magnesium screws showed screw breakage in the majority of cases. $\bf Evidence$ Controlled laboratory study

Results of Arthroscopic Revision Rotator Cuff Repair for Failed Open or Arthroscopic Repair: A Prospective Multicenter Study on 100 Cases

Background: Retears after rotator cuff repair (RCR) have been associated with poor clinical results. Meaningful data regarding the role of arthroscopic revision RCR are sparse thus far. Purpose/Hypothesis: To investigate results after arthroscopic revision RCR. We hypothesized that (1) arthroscopic revision RCR would lead to improved outcomes, (2) the clinical results would be dependent on tendon integrity and (3) tear pattern, tendon involvement, and repair technique would influence clinical and structural results. Study Design: Case series; Level of evidence 4. Methods: During a 40-month period, 100 patients who underwent arthroscopic revision RCR were prospectively enrolled in this multicenter study. Outcomes were evaluated preoperatively, at 6 months (6M), and at 24 months (24M) using the Constant score (CS), the Oxford Shoulder Score (OSS), and the Subjective Shoulder Value (SSV). Tendon integrity at 2 years was analyzed using magnetic resonance imaging. A total of 13 patients (13%) were lost to follow-up, and 14 patients (14%) had a symptomatic retear before the 24M follow-up. Results: All clinical scores improved significantly during the study period (CS: preoperative, 44 +/- 16; 6M, 58 +/- 22; 24M, 69 +/- 19 points; OSS: preoperative, 27 +/- 8; 6M, 36 +/- 11; 24M, 40 +/- 9 points; SSV: preoperative, 43% +/- 18%; 6M, 66% +/- 24%; 24M, 75% +/- 22%) (P = 2, and medial cuff failure were correlated with poorer SSV scores at 2 years (P <= .047). Patients with traumatic retears had better CS and OSS scores at 2 years (P <= .039). Conclusion: Although arthroscopic revision RCR improved shoulder function, retears were frequent but usually smaller. Patients with retears, however, did not necessarily have poorer shoulder function. Patient satisfaction at 2 years was lower when primary open RCR was performed, when a subscapularis tear or osteoarthritis was present, and when the rotator cuff retear was located at the musculotendinous junction. Patients with traumatic retears showed better functional improvement after revision

Surgical Treatment of Isolated Patellofemoral Osteoarthritis

Isolated patellofemoral osteoarthritis in the healthy middle-aged population is a challenging problem. Fifty-one knees in 50 patients with isolated patellofemoral osteoarthritis were treated by partial lateral facetectomy, lateral release, and medialization of the tibial tubercle. The minimum followup was 7 months (mean, 20.2 months; range, 7–32 months). Preoperative radiographs showed Ahlbäck Grades III and IV lateral patellofemoral joint space narrowing. The mean age of the patients was 60.1 years (range, 46–81 years). The subjective outcome was based on the WOMAC and the McCarroll score. Posteroanterior flexion weightbearing views, lateral views, and 45° axial views were taken. According to the WOMAC score, the scores improved considerably by 2.34 points with respect to pain and by 1.63 points with respect to function. The Insall-Salvati index decreased considerably but still remained in the physiologic range. The majority of these patients experienced improvement in their patellofemoral symptoms. However, the clinical outcome was not better in comparison to other surgical procedures. After the short followup, we would not recommend combined lateral facetectomy, lateral release, and medialization of the tibial tubercle until longer results are available