The arthroscopic treatment of anterior shoulder instability with glenoid bone loss shows similar clinical results after Latarjet procedure and iliac crest autograft transfer.

PURPOSE: Recurrent anterior shoulder instability caused by critical bone loss of the glenoid is a challenging condition for shoulder surgeons. The purpose of this prospective multicenter trial was to compare the arthroscopic transfer of the coracoid process (Latarjet procedure) with the arthroscopic reconstruction of the glenoid using iliac crest autografts. METHODS: A prospective multi-center trial was performed in nine orthopaedic centres in Austria, Germany and Switzerland between July 2015 and August 2021. Patients were prospectively enrolled and received either an arthroscopic Latarjet procedure or an arthroscopic iliac crest graft transfer. Standardized follow-up after 6 months and mimimum 24 months included range of motion, Western Ontario stability index (WOSI), Rowe score and subjective shoulder value (SSV). All complications were recorded. RESULTS: 177 patients (group Latarjet procedure: n = 110, group iliac crest graft: n = 67) were included in the study. WOSI (n.s.), SSV (n.s.) and Rowe score (n.s.) showed no difference at final follow-up. 10 complications were seen in group Latarjet procedure and 5 in group iliac crest graft; the frequency of complications did not differ between the two groups (n.s.). CONCLUSION: The arthrosopic Latarjet procedure and arthroscopic iliac crest graft transfer lead to comparable results regarding clinical scores, frequency of recurrent dislocations and complication rates. LEVEL OF EVIDENCE: Level II.

The lack of retropatellar resurfacing at index surgery is significantly associated with failure in patients following patellofemoral inlay arthroplasty: a multi-center study of more than 260 patients.

PURPOSE: To evaluate the clinical outcomes of patients with a minimum 2-year follow-up following contemporary patellofemoral inlay arthroplasty (PFIA) and to identify potential risk factors for failure in a multi-center study. METHODS: All patients who underwent implantation of PFIA between 09/2009 and 11/2016 at 11 specialized orthopedic referral centers were enrolled in the study and were evaluated retrospectively at a minimum 2-year follow-up. Clinical outcomes included the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, the Knee Injury and Osteoarthritis Outcome Score (KOOS), the Tegner Scale, the visual analogue scale (VAS) for pain, and subjective patient satisfaction. Pre- and perioperative risk factors were compared among failures and non-failures to determine potential risk factors. RESULTS: A total of 263 patients (85% follow-up rate) could be enrolled. The mean age at the time of index surgery was 49 ± 12 years with a mean postoperative follow-up of 45 ± 18 months. The overall failure rate was 11% (28 patients), of which 18% (5 patients) were patients with patella resurfacing at index surgery and 82% (23 patients) were patients without initial patella resurfacing. At final follow-up, 93% of the patients who did not fail were satisfied with the procedure with a mean transformed WOMAC Score of 84.5 ± 14.5 points, a mean KOOS Score of 73.3 ± 17.1 points, a mean Tegner Score of 3.4 ± 1.4 points and a mean VAS pain of 2.4 ± 2.0 points. An increased BMI was significantly correlated with a worse postoperative outcome. Concomitant procedures addressing patellofemoral instability or malalignment, the lack of patellofemoral resurfacing at the index surgery and a high BMI were significantly correlated with failure in our patient cohort. CONCLUSION: Patellofemoral inlay arthroplasty shows high patient satisfaction with good functional outcomes at short-term follow-up and thus can be considered a viable treatment option in young patients suffering from isolated patellofemoral arthritis. Patellar resurfacing at index surgery is recommended to decrease the risk of failure. LEVEL OF EVIDENCE: Retrospective case series, Level IV.

The acromiohumeral distance in the MRI should not be used as a decision criterion to assess subacromial space width in shoulders with an intact rotator cuff.

PURPOSE: The acromiohumeral distance is in practice often evaluated on MRI by radiologists and a reduction diagnosed as subacromial impingement. However, the acromiohumeral distance as indicator for a decentered glenohumeral joint is defined on a true AP radiograph with the patient standing or sitting. The present study therefore evaluated the influence of the patient position by comparing the acromiohumeral distance in both modalities in shoulders with an intact rotator cuff. METHODS: On MRI images and true AP radiographs of patients > 20 and < 80 years with an intact rotator cuff the acromiohumeral distance was measured. The maximum cranio-caudal size of the glenoid was measured as a reference to allow a direct comparison of both modalities. RESULTS: Two-hundred and thirty-four shoulders (mean patients age 45.8 ± 14.3 years) were included. The mean acromiohumeral distance/glenoid size ratio of all shoulders was significantly larger (P < 0.0001) on the MRI with 4.6 ± 1.0 in comparison to 4.1 ± 0.9 in the radiographs indicating a smaller acromiohumeral distance on the MRI. In absolute values, a mean acromiohumeral distance of 9.2 mm ± 1.8 on MRI in comparison to 10.4 mm ± 2.4 on the radiographs was calculated. Herewith, the acromiohumeral distance in the MRI was in the average 1.2 mm ± 2.1 (13%) smaller than the in corresponding radiographs (P < 0.0001). CONCLUSION: The acromiohumeral distance is significantly smaller in the MRI in comparison to AP radiographs in shoulders with an intact rotator cuff and should not be used as a decision criterion on MRI to assess glenohumeral centering or subacromial space width. LEVEL OF EVIDENCE: IV.

Editorial Commentary: Shoulder Biceps Tenodesis Implant Selection Requires Consideration of Complications and Cost.

The long head of biceps tendon (LHB) has been evaluated as one of the most important pain generators of the shoulder. In addition, an unstable LHB can cause cartilage lesions of the humerus. For the treatment of LHB lesions, tenodesis or tenotomy has been shown to be appropriate. A well-performed biceps tenodesis provides a lower rate of Popeye-sign deformities compared with tenotomy but must result in low implant complication rates and costs.

The association between a low critical shoulder angle and SLAP lesions.

PURPOSE: To evaluate the critical shoulder angle (CSA), acromion index (AI) and further acromion parameters in patients with isolated SLAP lesions compared with patients without SLAP lesions. METHODS: Between 2012 and 2016, the CSA, AI, lateral acromion angle (LAA) and acromion slope (AS) were radiologically examined in consecutive patients > 18 years having had a shoulder arthroscopy with isolated SLAP lesion types II-IV. These were compared to controls without SLAP lesions and without (control group I) or with (control group II) complete supraspinatus tendon (SSP) tears. RESULTS: 75/103 patients with isolated SLAP lesion types II-IV with a mean age of 46.5 years (± 13.0, 18.1-76.3) were analyzed, 61% of them being male. For control, n = 211 consecutive patients (47% male) with an intact SSP and SLAP complex and a mean age of 52.3 years (± 15.0, 18.6-88.4) and n = 115 patients (60% male) with an intact SLAP complex but complete SSP tears, mean age 66.6 years (± 9.3, 44.7-87.9) were examined. The CSA in SLAP patients was 29.6° (± 3.5, 21.0-38.0), 33.8° (± 3.7, 25.1-46.9) in no SLAP and no SSP (p < 0.001) and 36.7° (± 3.6, 29.1-46.6) in no SLAP but SSP (p < 0.001). The area under the curve (AUC) for CSA was 0.83 for SLAP lesions resulting in a probability of 83% for patients with SLAP lesion to be associated with a specific CSA. CONCLUSIONS: Isolated SLAP lesion types II-IV are associated with a low CSA < 30°. The AI, the AS as well as the LAA showed no correlation with SLAP lesions. LEVEL OF EVIDENCE: Retrospective comparative study, Level III.

Biceps tenodesis versus tenotomy in isolated LHB lesions: a prospective randomized clinical trial.

INTRODUCTION: Currently there exists no clear evidence concerning the surgical treatment of LHB lesions with either tenotomy or tenodesis. The aim of the study is therefore to evaluate elbow flexion and forearm supination force as well as the biceps muscle distalization according to both techniques in isolated LHB lesions. METHODS: Consecutive patients aged 40-70 years with shoulder arthroscopies for isolated SLAP or biceps pulley lesions were prospectively randomized to arthroscopic suprapectoral intraosseous LHB tenodesis or tenotomy. Pre-, 6 and 12 months postoperatively, the SST, ASES, Constant-Murley and LHB scores were recorded. The elbow flexion force was measured in 10°/90° flexion, the supination force in neutral/pronation position. In addition, the maximum upper-arm circumference and its position relative to the radial epicondyle of the humerus were evaluated preoperatively and in follow-up. RESULTS: 20/22 patients (mean age 52.0 ± 8.5; range 36-63 years, 11 male) completed the follow-up. 9/20 were treated with LHB tenodesis (mean age 51.5 ± 9.5; range 37-63 years, 7 male) and 11/20 with tenotomy (mean age 52.8 ± 8.0; range 36-62 years, 4 male). The force measurements and scores showed no significant difference after 12 months. Tenodesis achieved a significant increase in force 6 months postoperatively compared to preoperatively. One tenodesis patient and three tenotomy patients showed a postoperative popeye-sign deformity. CONCLUSION: This prospective randomized study comparing LHB tenodesis and tenotomy in isolated LHB lesions has shown no significant difference in elbow flexion and forearm supination force and clinical scores after 12 months. After LHB tenotomy, there was a non-significant trend for a higher rate of popeye-sign deformities of the upper arm and biceps muscle cramps.

Symptomatic medial synovial plica of the knee joint: an underestimated pathology in young patients.

INTRODUCTION: To prospectively evaluate the outcome of arthroscopic resection of a symptomatic medial plica in patients under 30 years with evaluating the influence of sports, knee trauma and plica type. METHODS: 35 consecutive patients (38 knees), mean age 16.2 ± 4.7 years (9-26 years), 28 females (73.7%) were prospectively included. Patients with any additional surgical procedures or cartilage lesions > ICRS grade I were excluded. The influence of trauma to the knee, level of sport and the morphologic plica type on the outcome was evaluated in addition to standard knee scores before and 20.1 ± 9.3 months (12-44 months) after surgery. RESULTS: The Knee Injury and Osteoarthritis Outcome Score improved significantly from 50.2 ± 19.1% (12.5-94.6) to 80.7 ± 15.3% (48.2-100; p < 0.001). The Tegner Activity Scale improved significantly from 2.2 ± 1.5 (0-6) to 4.9 ± 1.7 (3-10; p < 0.001) and the Kujala Anterior Knee Pain Scale improved significantly from 52.6 ± 16.6 (16-86) to 80.7 ± 16.5 (46-100; p < 0.001). The level of pain in the knee decreased from 7.9 ± 2.0 (1-10) to 3.1 ± 2.6 (0-9; p < 0.001) at follow-up on a numeric rating scale (0-10). Neither trauma to the knee, high impact sport, cartilage lesions to the medial femoral condyle nor the plica type or associated ICRS grade I cartilage lesion to the medial femoral condyle had a significant effect on the outcome parameters. CONCLUSION: Arthroscopic resection of a symptomatic medial plica provides excellent clinical results in young patients. Trauma, high impact sports, ICRS grade I cartilage lesions to the medial femoral condyle or the plica type are not associated with a poorer outcome. LEVEL OF EVIDENCE: Level IV, prospective case series with no control group.

Prevalence of Propionibacterium acnes in the glenohumeral compared with the subacromial space in primary shoulder arthroscopies.

HYPOTHESIS: We hypothesized that the prevalence of Propionibacterium acnes in patients undergoing primary shoulder arthroscopy is equal in the glenohumeral space compared with the subacromial space. METHODS: Patients aged 18 years or older with shoulder arthroscopies were included. The exclusion criteria were prior shoulder operations, complete rotator cuff tears, systemic inflammatory diseases, tumors, shoulder injections within 6 months of surgery, and antibiotic therapy within 14 days preoperatively. After standardized skin disinfection with Kodan Tinktur Forte Gefärbt, a skin swab was taken at the posterior portal. Arthroscopy was performed without cannulas, prospectively randomized to start either in the glenohumeral space or in the subacromial space, with direct harvesting of a soft-tissue biopsy specimen. Sample cultivation was conducted according to standardized criteria for bone and joint aspirate samples and incubated for 14 days. Matrix-assisted laser desorption-ionization time-of-flight spectrometry was used for specimen identification in positive culture results. RESULTS: The study prospectively included 115 consecutive patients with normal C-reactive protein levels prior to surgery (54.8% men; mean age, 47.2 ± 14.6 years). P acnes was detected on the skin after disinfection in 36.5% of patients, in the glenohumeral space in 18.9%, and in the subacromial space in 3.5% (P = .016). CONCLUSION: The prevalence of P acnes is significantly higher in the glenohumeral space compared with the subacromial space in primary shoulder arthroscopies. The results do not confirm the contamination theory but also cannot clarify whether P acnes is a commensal or enters the joint hematologically or even lymphatically or via an unknown pathway. Despite standardized surgical skin disinfection, P acnes can be detected in skin swab samples in more than one-third of patients.

The influence of suprapectoral arthroscopic biceps tenodesis for isolated biceps lesions on elbow flexion force and clinical outcomes.

PURPOSE: To prospectively evaluate elbow flexion force, cosmetic and clinical outcome of all-arthroscopic suprapectoral biceps tenodesis for isolated biceps lesions. METHODS: Tenodesis was performed using a 6.25-mm absorbable interference screw for intraosseous fixation. Seventeen out of 24 patients (70.8 %, median age 49.0 ± 10.1 years; 10 = male) could be included for 24 months follow-up. Elbow flexion strength in 10° and 90° elbow flexion, the upward-directed force of the upper arm in the O'Brien position, objective evaluation of a Popeye-sign deformity and validated clinical scores (CMS, SST, ASES) were assessed preoperatively, 3, 6, 12 and 24 months postoperatively. RESULTS: Elbow flexion strength in 90° improved significantly from 12 months onwards (P = 0.001) without significant difference to the contralateral arm from 3 months postoperatively (n.s.). At 24 months, an average increase of 46.4 % (median 37.7 %) from preoperative could be seen. The dominant arm was affected in 70.6 %. All scores showed a significant improvement 3 months postoperatively: SST (P = 0.003), ASES (P = 0.006) and total CMS (P < 0.001). Three patients (17.6 %) developed a distalization of the maximum biceps circumference of more than 20 % compared to preoperative. CONCLUSIONS: All-arthroscopic proximal suprapectoral intraosseous single-limb biceps tenodesis for the treatment of isolated biceps lesions provides good-to-excellent clinical results with significant improvement of elbow flexion strength and clinical scores and no significant difference to the unaffected contralateral arm. LEVEL OF EVIDENCE: IV.

Surgical treatment of patellar instability: clinical and radiological outcome after medial patellofemoral ligament reconstruction and tibial tuberosity medialisation.

INTRODUCTION: The aim of this retrospective study was to analyse clinical and radiological outcome after medial patellofemoral ligament reconstruction (MPFLR) and tibial tuberosity medialisation (TTM) in patients with recurrent patellar instability. MATERIALS AND METHODS: Thirty-five patients were included between 2008 and 2012. According to defined criteria such as tibial tuberosity-trochlear groove (TTTG) distance, hyperpression on the lateral patella facet and lateral retropatellar cartilage damage either MPFLR (group A) or TTM (group B) was performed: 18 patients underwent TTM, the other 17 patients underwent MPFLR. At a mean of 25.4 ± 9.7 (group A) and 35.2 ± 17.6 months (group B) patients were clinically and radiologically reviewed. Validated knee scores such as Kujala, Lysholm and Tegner score were evaluated. RESULTS: In both groups one patient reported of a non-traumatic patellar redislocation. Patients who underwent MPFLR (group A) had less pain postoperatively during activity according to the Visual Analogue Scale (group A: 2.0 ± 2.1 points, group B: 3.9 ± 2.3 points). Retropatellar cartilage damage increased in group B from grade 1 (range: 1-3) preoperatively to grade 2 (range 1-3) postoperatively (p > 0.05). All other clinically evaluated items, as well as the applied knee scoring systems, indicated no significant difference (p > 0.05) and displayed good to excellent results. CONCLUSIONS: MPFLR and TTM leed to good clinical results despite its own indications. For this reason-in selected cases-TTM may still be a suitable procedure for surgical treatment of patellar instability. However, patients treated by TTM (group B) revealed an increased retropatellar cartilage damage as well as significantly more pain during activity.

Arthroscopically assisted retrograde drilling of the humeral head with a guiding device.

This manuscript describes the successful treatment of a steroid-induced avascular necrosis of the humeral head using arthroscopically assisted retrograde drilling of a stage II lesion using a guiding device. At the final follow-up 19 month post-operatively, the patient presented pain-free without functional limitations although the osteonecrosis had not been fully healed.

Joint failure after steroid therapy in tuberculous encephalitis.

We report a case of multifocal avascular osteonecrosis (AVN) following steroid administration in a case of tuberculous encephalitis in a young patient. The risk of joint-related AVN as a side effect of adjunctive steroid therapy should be taken into consideration when evaluating the dosage and treatment duration in tuberculous encephalitis.

Penetration of topical diclofenac sodium 4 % spray gel into the synovial tissue and synovial fluid of the knee: a randomised clinical trial.

PURPOSE: The present study was designed to evaluate the penetration of diclofenac sodium 4 % spray gel in synovial tissue, synovial fluid and blood plasma after topical application in subjects with joint effusions and planned total knee arthroplasty (TKA) due to osteoarthritis. METHODS: A total of 39 patients were randomised to two- or three-times daily application of diclofenac sodium 4 % spray gel to knees requiring surgery over a treatment period of 3 days. Within 8 h after the last application, TKA was conducted, and the diclofenac concentrations in synovial tissue, synovial fluid and blood plasma were measured by liquid chromatography. RESULTS: The median diclofenac concentration was approximately 10-20-fold higher in synovial tissue (36.2 and 42.8 ng/g) than in synovial fluid (2.6 and 2.8 ng/mL) or plasma (3.9 and 4.1 ng/mL) in both treatment groups. Dose proportionality for any compartment or treatment groups could not be detected. Treatment-related adverse events were noted in two cases and limited to skin reactions. CONCLUSION: Diclofenac sodium 4 % spray gel was found to penetrate the skin locally in substantial amounts and thus reach the desired target tissue. Concentrations were not dose-dependent, and application was well tolerated by 97.4 % of patients. Topical application of diclofenac should be considered a valuable alternative to systemic NSAID therapy in the initial treatment of osteoarthritis.

Neuromuscular Electrical Stimulation-Enhanced Physical Therapist Intervention for Functional Posterior Shoulder Instability (Type B1): A Multicenter Randomized Controlled Trial.

OBJECTIVE: Functional posterior shoulder instability (FPSI) (type B1) is a severe type of instability, mainly in teenagers and young adults, that leads to loss of function, pain, and stigmatization among peers. An experimental nonsurgical treatment protocol based on neuromuscular electrical stimulation (NMES) showed very promising early results in the treatment of FPSI. The hypothesis of this study was that NMES-enhanced physical therapy leads to better outcomes than physical therapy alone as the current gold standard of treatment in patients with FPSI. METHODS: In this multicenter randomized controlled trial, patients with FPSI were randomly allocated in a 1:1 ratio to either 6 weeks of physical therapy or 6 weeks of physical therapy with simultaneous motion-triggered NMES. Baseline scores as well as outcome scores at 6 weeks, 3 months, 6 months, and 12 months after the intervention were obtained. The predefined primary outcome of this trial was the Western Ontario Shoulder Instability Index (WOSI) at the 3-month time point. RESULTS: Forty-nine patients were randomized and eligible for the trial. The group that received physical therapy with simultaneous motion-triggered NMES showed a significantly better main outcome measurement in terms of the 3-month WOSI score (64% [SD = 16%] vs 51% [SD = 24%]). Two-thirds of the patients from the physical therapist group crossed over to the group that received physical therapy with simultaneous motion-triggered NMES due to dissatisfaction after the 3-month follow-up and showed a significant increase in their WOSI score from 49% [SD = 8%] to 67% [SD = 24%]. The frequency of instability episodes showed a significant improvement in the group that received physical therapy with simultaneous motion-triggered NMES at the 3-month follow-up and beyond, while in the physical therapist group, no significant difference was observed. CONCLUSION: The current study shows that NMES-enhanced physical therapy led to statistically significant and clinically relevant improvement in outcomes in the treatment of FPSI compared to conventional physical therapy alone-from which even patients with prior unsatisfactory results after conventional physical therapy can benefit. IMPACT: Based on the results of this study, NMES-enhanced physical therapy is an effective new treatment option for FPSI, a severe type of shoulder instability. NMES-enhanced physical therapy should be preferred over conventional physical therapy for the treatment of patients with FPSI.

Biomechanical comparison of open and arthroscopic Latarjet procedures.

PURPOSE: To biomechanically compare the effectiveness of the standard open and arthroscopic techniques of the Latarjet procedure to address a critical anterior glenoid defect in combination with a capsular insufficiency. METHODS: Translation testing of 12 human cadaveric shoulder specimens was performed in a robot-assisted setup under 3 different conditions: (1) intact/vented shoulder joint, (2) combined anterior glenoid bone and capsular defect, and (3) open and arthroscopic Latarjet procedures. Testing was performed for each condition in 2 test positions: 60° of glenohumeral abduction with neutral rotation (ABD position) and 60° of abduction and external rotation (ABER position). Each position was tested with a passive humerus load of 30 N in the anterior, inferior, and anteroinferior directions. Translational movement of the humeral head was evaluated with and without the application of a 10-N load to the conjoint tendon (CJT). RESULTS: In the ABD position, translations after the open Latarjet procedure significantly differed from the arthroscopic technique in the anterior and anteroinferior directions when testing was performed with loading of the CJTs (CJT loading). Without CJT loading, the open Latarjet technique showed significantly lower translations in the anterior, inferior (P = .004), and anteroinferior (P = .001) testing directions in the ABD position. In the ABER position, the arthroscopic procedure showed no significant difference compared with the standard open procedure. CONCLUSIONS: We found a superior stabilization effect of the open Latarjet technique in the ABD position. The difference is ascribed to the anterior capsular repair, which was performed within the open technique and omitted during the arthroscopic procedure. CLINICAL RELEVANCE: The reduction of translation in a pure abduction position of the arm is more effectively performed with a conventional open Latarjet technique that includes a capsular repair. In combined ABER position, there was no difference found between the open and arthroscopic Latarjet techniques.

Do anatomic variants of the acromion shape in the frontal plane influence pain and function in calcifying tendinitis of the shoulder?

PURPOSE: To evaluate the relationship of a large acromion index and calcifying tendinitis of the supraspinatus tendon at the shoulder. MATERIALS AND METHODS: Between 2002 and 2008, 109 consecutive patients with isolated calcifying tendinitis of the supraspinatus tendon were prospectively analysed by clinical investigation and standardized radiographs. Deposit size and appearance were measured and classified according to Bosworth and Gartner. The acromion index (AI) was calculated based on measurements on true anteroposterior radiographs. Pain record on VAS scale, active and passive range of motion and the constant score (CS) were recorded. RESULTS: The mean age of the patients was 48.2 ± 8.0 (n = 46 male 48.6 ± 7.3; n = 63 female 47.9 ± 8.6; P > 0.05). Pain and function were not significantly correlated with deposit size or classification. The acromion index (mean 0.64 ± 0.08) was not significantly correlated with the affected or dominant side, gender, deposit size or classification or any functional parameter like pain and the CS or its subgroups. CONCLUSION: The theoretical concept of a high acromion index resulting in an increased resulting upward force against the subacromial space, which influences pain and function in calcifying tendinitis of the shoulder, was not supported.

Suprapectoral or subpectoral position for biceps tenodesis: biomechanical comparison of four different techniques in both positions.

HYPOTHESIS: The aim of this study was to compare different techniques for tenodesis of the long head of biceps tendon (LHB) in the suprapectoral and subpectoral position to test the hypothesis that using shorter screws at the subpectoral position would achieve a similar primary ultimate failure load (UFL) as the longer screws at the suprapectoral position, that both types of tenodesis screws achieve comparable UFL, and that knotless suture anchor techniques can be performed at the subpectoral position in cortical bone and reach a UFL similar to tenodesis screws. METHODS: On 42 fresh frozen human cadavers divided into 6 groups, 4 different techniques for LHB tenodesis were performed localized 10 mm and 50 mm, respectively, distal to the entrance of the bicipital groove. Two techniques with tenodesis screws (Bio-Tenodesis screw, Biceptor) and 2 with knotless suture anchors (Bio-SwiveLock, Footprint PK) were tested. Under a 10-N preload, an axial cyclic load with 100 cycles, 1-Hz frequency, and 50-N maximal load was applied. UFL was evaluated with an axial traction of 0.2 mm/s until decrease of tension. LHB dislocation was measured by 3-dimensional photogrammetry. RESULTS: All techniques except the subpectoral Bio-SwiveLock had a dislocation <3 mm after cyclic loading. The highest mean UFL was measured for the suprapectoral Bio-Tenodesis screw (218.3 ± 59.7 N) and the lowest with the subpectoral Footprint PK (99.1 ± 16.4 N). The UFL of suture anchors were significantly lower than those of interference screws (P < .01). UFL was not significantly different for type of interference screw, the type of suture anchor, or tenodesis localization. Different failure mechanisms were evaluated for suture anchors and interference screws. CONCLUSION: Due to the biomechanical testings interference screws are appropriate devices for suprapectoral and subpectoral biceps tenodesis resisting cyclic loading and attaining a satisfactory, whereas the knotless suture anchors sustained a significant about 50% lower UFL, and can only be recommended conditionally for LHB tenodesis regarding primary stability.

The influence of superior labrum anterior to posterior (SLAP) repair on restoring baseline glenohumeral translation and increased biceps loading after simulated SLAP tear and the effectiveness of SLAP repair after long head of biceps tenotomy.

HYPOTHESIS: Biomechanical studies have shown increased glenohumeral translation and loading of the long head biceps (LHB) tendon after superior labrum anterior to posterior (SLAP) tears. This may explain some of the typical clinical findings, including the prevalence of humeral chondral lesions, after SLAP lesions. The first hypothesis was that SLAP repair could restore the original glenohumeral translation and reduce the increased LHB load after SLAP lesions. The second hypothesis was that SLAP repair after LHB tenotomy could significantly reduce the increased glenohumeral translation. MATERIALS AND METHODS: Biomechanical testing was performed on 21 fresh frozen human cadaveric shoulders with an intact shoulder girdle using a sensor-guided industrial robot to apply 20 N of compression in the joint and 50 N translational force at 0°, 30°, and 60° of abduction. LHB loading was measured by a load-cell with 5 N and 25 N preload. Type IIC SLAP lesions were created arthroscopically, and a standardized SLAP repair was done combined with or without LHB tenotomy. RESULTS: No significant difference of glenohumeral translation and increased LHB load in SLAP repair compared with the intact shoulder was observed under 5 N and 25 LHB preload, except for anterior translation under 25 N LHB preload. After LHB tenotomy after SLAP lesions, no significant difference of translation was observed with or without SLAP repair. CONCLUSIONS: SLAP repair without associated LHB tenotomy helps normalize glenohumeral translation and LHB loading. The stabilizing effect of the SLAP complex is dependent on the LHB. After biceps tenotomy, SLAP repair does not affect glenohumeral translation.

Anterior cruciate ligament deficiency leads to early instability of scaffold for cartilage regeneration: a controlled laboratory ex-vivo study.

PURPOSE: The affect of anterior cruciate ligament (ACL) integrity on the early postoperative stability of a collagen type-I gel scaffold was investigated. The value of fibrin glue for graft fixation in ACL deficient porcine knees over a simulated early postoperative period was also studied. METHODS: Full-thickness articular cartilage defects (11 × 6 mm) were created on the medial femoral condyle of 80 porcine knees. The ACL was left intact or completely transected in each of 40 knees. Gel plugs were tested in each group: press-fitting only in 20 specimens and press-fitting plus fibrin glue in 20 specimens. Each knee underwent 2,000 cycles in a validated ex-vivo continuous passive motion model. RESULTS: Press-fit-only fixation grafts in knee specimens with an intact ACL showed significantly superior stability than that in ACL deficient knees (p = 0.01). In ACL deficient knees, grafts fixed with press-fitting plus fibrin glue showed significantly superior stability than those using press-fit only fixation (p = 0.01). Press-fitting plus fibrin glue fixation showed no significant differences in worn surface area between knee specimens with intact and deficient ACL. CONCLUSIONS: ACL deficiency led to early scaffold instability in an ex-vivo porcine knee model. Fibrin glue in ACL deficient knees led to additional graft stability. These findings indicated that cartilage regenerative techniques may give optimum results in ACL intact knees.

Physiology and pathophysiology of nitrosative and oxidative stress in osteoarthritic joint destruction.

Osteoarthritis (OA) is one of the most common chronic diseases, with increasing importance due to increased life expectancy. On a cellular level, the pathophysiology of joint function impairment and ultimate destruction associated with OA remains poorly understood. Free radicals are highly reactive molecules involved in both normal intracellular signal transduction and degenerative cellular processes. An imbalance between the free radical burden and cellular scavenging mechanisms, defined as oxidative stress, has been identified as a relevant factor in OA pathogenesis. This literature review elucidates the involvement of nitrosative and oxidative stress in cellular ageing in joints, cell senescence, and apoptosis. Free radical exposure is known to promote cellular senescence and apoptosis, and the involvement of radical oxygen species (ROS) in inflammation, fibrosis control, and pain nociception has been proven. A relatively novel approach to OA pathophysiology considers the joint to be a dynamic system consisting of 3, continuously interacting compartments, cartilage, synovial tissue, and subchondral bone. Current knowledge concerning free radical involvement in paracrine signalling in OA is reviewed. The interrelationship between oxidative imbalances and OA pathophysiology may provide a novel approach to the comprehension, and therefore modification, of OA disease progression and symptom control.