Prognostic factors and therapeutic options for treatment of frozen shoulder: a systematic review.

PURPOSE: To evaluate the current status of scientific research on the natural history of frozen shoulder as published in the literature. MATERIALS AND METHODS: This systematic review was carried out on PubMed data and was guided by PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses). Articles had to meet inclusion criteria. The quality of the papers was assessed using a newly developed tool, AMQPP (Assessing the Methodological Quality of Published Papers). The AMQPP score was correlated with the level of evidence rating according to the Oxford Centre for Evidence-Based Medicine. Suitable papers were divided into groups according to the shoulder condition on which they reported. This article focuses on the frozen shoulder. RESULTS: Seven articles on frozen shoulder met the inclusion criteria. One article was considered to have level 1 of evidence. Three articles had level 3 and the remaining 3 had level 4. Three papers assessed the natural history and the natural course of different forms of stiff shoulder. The others indirectly assessed the natural history by evaluating therapy trends. None of the articles clearly referred to the role of regression to the mean of frozen shoulder specifically. CONCLUSION: Spontaneous recovery to normal levels of function is possible and standardised non-operative treatment programmes are an effective alternative to surgery in most cases. However, patients with high risk factors such as diabetes mellitus, and those who suffer chronic symptoms or bilaterally affected, would benefit from early surgery. We also concluded that AMQPP score is simple and straight forward. It works as a quick quality-checking tool which helps researchers to identify the key points in each paper and reach a decision regarding the eligibility of the paper more easily. The AMQPP score is still open for further development.

Duration of sick leave after shoulder arthroscopy in Germany: analysis of health care data.

INTRODUCTION: The expected duration of incapacity after arthroscopic shoulder surgery is an important factor for therapy planning. The aim of this study was to analyze the duration of sick leave after arthroscopic shoulder surgery in Germany and to identify factors associated with a longer duration of sick leave. We hypothesized that certain patient-related factors may be associated with a longer duration of sick leave. METHODS: Routine health care data of all patients insured by one German health insurance company who underwent inpatient arthroscopic shoulder surgery between 2010 and 2012 were included in the analysis of the duration of sick leave in this retrospective cohort study (level III evidence). Comparisons were performed for different arthroscopic surgical procedures using the log-rank test. Possible factors that might be associated with a longer duration of incapacity were analyzed. RESULTS: Sick leave was reported in 303 of 660 cases. The median duration of sick leave was 82 days after subacromial decompression and 157 days after rotator cuff repair (p = 0.004). The duration of sick leave was longer in patients older than 50 years (p = 0.044) and in patients with sick leave that started prior to surgery (p < 0.001). Patients not receiving physiotherapy had a longer period of sick leave (p = 0.058). The median period of prescribed physiotherapy (64 days) was shorter than the period of incapacity. The duration of disability was not notably longer in female patients, patients taking opioid or antidepressant medication or diabetics. CONCLUSIONS: The duration of sick leave after arthroscopic shoulder surgery in Germany does not exceed sick leave duration in other countries. More complex procedures, advanced age and sick leave beginning prior to surgery resulted in longer durations of sick leave. Preoperative prognosis of the necessary duration of postoperative sick leave may not always be realistic. An extended period of sick leave can be expected after more complex procedures and in patients older than 50 years of age. Future studies should investigate whether a longer period of physiotherapy may help to shorten the period of postoperative sick leave.

The natural history of rotator cuff tears: a systematic review.

PURPOSE: To analyse the current scientific evidence regarding the natural history of the clinical and anatomical progression of rotator cuff tears. METHODS: A broad systematic review of the literature (PubMed database through January 2014) which was guided, conducted and reported according to PRISMA criteria. This article focuses on the rotator cuff tears. Articles had to meet an inclusion criteria. The methodological quality of each study was individually assessed using a recently developed general assessment tool AMQPP (assessing the methodological quality of published papers). RESULTS: Seven articles dealing with rotator cuff tears were included, one of them was a high-quality study. Three papers assessed the natural history and the natural course of rotator cuff rupture directly. The other studies indirectly assessed the natural history with reports on non-operative and operative therapy trends. All of these articles had been published in four different top medical journals according to 2013 ranking. We found no articles which clearly referred to the role of regression to the mean of rotator cuff tears. CONCLUSION: The development of symptoms and anatomical deterioration are often directly correlated. Spontaneous recovery to normal levels of function has been successfully achieved, and standardised non-operative treatment programmes are an effective alternative to surgery for many patients. Follow-up is necessary to avoid irreparable stage. However, surgery is still favoured by young active people and highly professional persons who need to get fit in a short period of time. Further research is still necessary. The AMQPP score system is simple and reliable. It works as a quick quality-checking tool which helps researchers to identify the key points in each paper and reach a decision regarding the eligibility of the paper more easily.

Which Factors Are Associated With Rerupture After Superior Capsular Reconstruction of the Shoulder With Autologous Long Biceps Tendon? - A Systematic Review. / Welche Faktoren sind mit einer Reruptur nach superiorer Kapselrekonstruktion der Schulter mit autologer langer Bizepssehne assoziiert? ­ Ein systematischer Review.

Based on a systematic review, the present work analyses factors associated with the rerupture rate or non-healing after superior capsular reconstruction with autologous long biceps tendon in the reconstruction of the rotator cuff of the shoulder.A systematic review of the U.S. National Library of Medicine/National Institutes of Health (PubMed) database and the Cochrane Library was conducted in September 2021 using the PRISMA checklist. Articles were identified and analysed that contained data on the rerupture rate after superior capsular reconstruction with autologous long biceps tendon in reconstruction of the rotator cuff of the shoulder. The aim was to identify factors associated with rerupture or non-healing. The risk of bias was determined using the Newcastle-Ottawa scale.Primarily 86 hits could be generated. Seven articles from 2020 and 2021 met the inclusion criteria and were further analysed in terms of content. The evidence level was III to IV. Follow-up was between 12 (minimum) and 24 to 48 months. The risk of bias was not low. Factors that may be associated with rerupture or non-healing are diabetes mellitus and high-grade fatty degeneration of the subscapularis, infraspinatus, or teres minor as preoperative factors. Age, percent footprint coverage, tear size, symptom duration, number of bundles, acromioplasty performed, and tear configuration were not significant factors. Gender, degree of fatty degeneration of the supraspinatus and lesions of the subscapularis tendon were rated differently.According to the literature, but still currently with short-term observation periods, superior capsular reconstruction with an autologous long biceps tendon is another treatment option in the case of massive tears and elderly patients, if there is no high-grade fatty degeneration of the subscapularis, infraspinatus or teres minor. Diabetes mellitus has an unfavorable prognosis. Additional acromioplasty has so far not been associated with better outcomes.

Risk Analysis of Perioperative Injections in Arthroscopic Reconstruction of the Rotator Cuff of the Shoulder - A Systematic Review. / Risikoanalyse perioperativer Infiltrationen bei arthroskopischer Rotatorenmanschettennaht der Schulter ­ ein systematischer Review.

BACKGROUND: The present study used a systematic review to analyse the risk of perioperative injections during arthroscopic reconstruction of the rotator cuff of the shoulder. The questions of interest were whether perioperative local injection increases the infection risk and whether the number of postoperative revisions is increased. MATERIAL AND METHODS: A systematic review of the U. S. National Library of Medicine/National Institutes of Health (PubMed) database and the Cochrane Library was performed using the PRISMA checklist. The keywords used were "shoulder" and "arthroscopy" and "injection" and "risk". In the course of the study, work that was not also primarily concerned with the reconstruction of the rotator cuff was excluded. English original articles and case series were included that contained at least some arthroscopic reconstructions of the rotator cuff. The risk of bias was determined using the Newcastle-Ottawa Scale. The content of the articles relevant to the research questions was analysed. RESULTS: 48 hits were primarily generated. 9 articles corresponded to the inclusion criteria and were analysed. In the 6 studies with details on the injected substances, cortisone was used in 98 - 100% of the cases. The reported infection and revision rates based on insurance data were higher with injection than without. The risk of bias in the studies analysed here was rather low based on the Newcastle-Ottawa Score. The risk of infection after a cortisone injection before, during or after surgery was increased. Injection was associated with infection in up to 8% of cases with injections within two weeks of surgery. The risk of infection was increased by up to 11 times with injections within 4 weeks after the operation. Likewise, the risk of revision surgery after injection was increased, with the time intervals between injection and surgery sometimes differing between studies. DISCUSSION: Local infections and to a lesser extent revision surgery are associated with perioperative injections (with cortisone) within 3 months preoperatively and 4 weeks postoperatively. However, there were only database studies of insurance data with several studies from a few centres. Thus, no causal relationships could be proven. Currently, however, the following can be recommended using a cautious approach: The interval between injection with cortisone before surgery should be at least 2 weeks, better 3 months. No cortisone injections should be applied intraoperatively. Postoperatively, cortisone should not be injected for at least 4 weeks. If, in exceptional cases, deviations from these time limits are required, patients should be informed about an increased risk of complications.

Calcitonin substitution in calcitonin deficiency reduces particle-induced osteolysis.

BACKGROUND: Periprosthetic osteolysis is a major cause of aseptic loosening in joint arthroplasty. This study investigates the impact of CT (calcitonin) deficiency and CT substitution under in-vivo circumstances on particle-induced osteolysis in Calca -/- mice. METHODS: We used the murine calvarial osteolysis model based on ultra-high molecular weight polyethylene (UHMWPE) particles in 10 C57BL/6J wild-type (WT) mice and twenty Calca -/- mice. The mice were divided into six groups: WT without UHMWPE particles (Group 1), WT with UHMWPE particles (Group 2), Calca -/- mice without UHMWPE particles (Group 3), Calca -/- mice with UHMWPE particles (Group 4), Calca -/- mice without UHMWPE particles and calcitonin substitution (Group 5), and Calca -/- mice with UHMWPE particle implantation and calcitonin substitution (Group 6). Analytes were extracted from serum and urine. Bone resorption was measured by bone histomorphometry. The number of osteoclasts was determined by counting the tartrate-resistant acid phosphatase (TRACP) + cells. RESULTS: Bone resorption was significantly increased in Calca -/- mice compared with their corresponding WT. The eroded surface in Calca -/- mice with particle implantation was reduced by 20.6% after CT substitution. Osteoclast numbers were significantly increased in Calca -/- mice after particle implantation. Serum OPG (osteoprotegerin) increased significantly after CT substitution. CONCLUSIONS: As anticipated, Calca -/- mice show extensive osteolysis compared with wild-type mice, and CT substitution reduces particle-induced osteolysis.

Femoral component rotation in patients with leg axis deviation.

PURPOSE: Correct alignment of the rotation of the femoral component and the flexion gap after total knee arthroplasty is difficult in patients with preoperative leg axis deviation. Inaccuracy may result in problems with the patellofemoral joint and instability, in particular. We examined the influence of the preoperative leg axis on the rotation of the femoral component and the symmetry of the flexion gap after total knee arthroplasty using the tibial-cut-first technique. METHODS: A retrospective study was carried out of 58 consecutive patients who underwent primary LCS total knee arthroplasty using the tibial-cut-first technique in 2008 based on preoperative full-leg radiographs and the final radiographs taken according to Kanekasu's technique. The patients were divided into three groups (varus-valgus-neutral) according to their preoperative leg axis. RESULTS: Using the tibial-cut-first technique, a mean neutral rotation of the femoral component of 0.5° and a mean symmetrical flexion gap of -0.7° were achieved. Nevertheless, there was a positive correlation of the preoperative leg axis with the rotation of the femoral component. The differences in the rotation of the femoral component and the flexion gap between the three groups were not significant. The only significant difference between the varus and valgus groups was the extent of rotation of the femoral component, with a slightly greater external rotation of 2.7° in the valgus group. CONCLUSIONS: This study suggests that it is possible to achieve correct rotational alignment of the femoral component and a symmetrical flexion gap using the tibial-cut-first technique in patients with a preoperatively deviated leg axis.

Motor Recovery of the Suprascapular Nerve after Arthroscopic Decompression in the Scapular Notch - a Systematic Review. / Die motorische Erholung der Rotatorenmanschette nach arthroskopischer proximaler Dekompression des N. suprascapularis in der Incisura scapulae ­ ein systematischer Review.

BACKGROUND: The suprascapular nerve can be compromised as a result of a compression syndrome in different locations. A (proximal) compression within the scapular notch can lead to dorsal shoulder pain and simultaneous weakness of the infraspinatus and supraspinatus muscles. By transection of the lig. transversum this compression syndrome can be treated. By means of a systematic review, the present work analyzes the motor recovery potential after arthroscopic decompression. MATERIAL AND METHODS: A systematic review of the U. S. National Library of Medicine/National Institutes of Health (PubMed) database and the Cochrane Library was performed using the PRISMA checklist. The search words used were "suprascapular" and "arthroscopic"; "suprascapular" and "arthroscopy". Based on the evaluated literature, articles in English with at least a partial arthroscopic case series from 4 cases on and a compression syndrome of the suprascapular nerve treated with arthroscopic decompression in the scapular notch were identified. Motor recovery was described by means of EMG, clinical strength and MRI. RESULTS: Primarily 408 hits were generated. Six articles met the inclusion criteria and were further analyzed. The number of arthroscopic cases was between 4 and a maximum of 27. The level of evidence was between III and IV. The majority of the reported clinical results were good. Motor recovery as measured by EMG was observed, recovery of full strength was not achieved in the majority of reported cases (60%), neither was regression of structural (fatty) degeneration of the muscle bellies. CONCLUSION: Arthroscopic decompression of the suprascapular nerve in the scapular notch provides good clinical results and considerable pain relief. However, in the majority of cases it does not lead to a complete recovery of the strength of the supra- and infraspinatus muscles. Patients should be informed about this. An early decompression after diagnosis in the event of proximal compression within the suprascapular notch combined with beginning EMG or MRI changes appears reasonable. These beginning changes should be further defined. Future studies should develop prognostic criteria for motor recovery. Awareness regarding the diagnosis needs to be improved due to the probably time-dependent irreversibility of resulting muscular weakness.

Biochemical markers of particle induced osteolysis in C57BL/6 mice.

BACKGROUND: Micro-structural changes associated with ultra high molecular weight polyethylene particle (UHMWPE) induced osteolysis, the most frequent cause of aseptic loosening, have been intensively investigated in the mammalian calvarian model by histomorphometry and micro-computed tomography. However, little is known regarding the serological changes that occur during this process. METHODS: Serological parameters for bone metabolism [calcium, phosphate, osteocalcin (OCN), deoxypyridinoline (DPD)/creatinine, alkaline phosphatase, osteoprotegerin and receptor activator of nuclear factor-κB] were analyzed in this animal model for particle induced osteolysis. Ten C57BL/6 mice were divided at random into sham operated and UHM-WPE implanted groups. Blood and urine samples were collected prior to and at 14 days after surgery. RESULTS: Implantation of UHMWPE lead to a significant decrease in bone volume (p=0.027). Both groups (sham/UHMWPE) showed a significant increase in calcium (p=0.004/p=0.027) and phosphate (p=0.001/p=0.001), without correlation to particle implantation. Significantly higher concentrations of DPD/creatinine (p=0.034) and OCN (p=0.022) were found after implantation of UHM-WPE. In addition, parameters could not be correlated to particle induced osteolysis. CONCLUSIONS: DPD can be regarded as a valuable parameter for detecting UHMWPE induced osteolysis in the calvarian model. Further studies of serum parameters should focus on the clinical relevance in aseptic prosthetic loosening.

Tartrate-resistant acid phosphatase 5b and C-terminal telopeptides of type I collagen as markers for diagnosis of aseptic loosening after total hip replacement.

INTRODUCTION: Plain radiography, bone scintigraphy, digital subtraction arthrography and various other techniques can be used to evaluate loosening of hip replacements. These methods are associated with radiation exposure and some of them have an increased morbidity. Furthermore, in some cases the results are not conclusive. METHOD: The osteoclast biomarkers tartrate-resistant acid phosphatase 5b (TRAP 5b) and C-terminal telopeptides of type I collagen (CTX) in serum taken from 12 patients with aseptic loosening were measured. Serum samples from 24 other patients, 12 with an intact arthroplasty and 12 without any kind of joint replacement, served as control groups. RESULTS: The serum level of CTX was increased in comparison to the control groups, but the differences were not significant. In contrast, the increase in TRAP 5b in patients with aseptic loosening was highly significant (P < 0.001). A TRAP 5b value of 3.365 U/L was determined as a cut-off value, giving a sensitivity of 83.3% and specificity of 91.7% to differentiate the patients with aseptic loosening from those with an intact arthroplasty. Measurement of serum TRAP 5b may be a clinically relevant assay for monitoring patients after arthroplasty.

Femoral component rotation and Laurin angle after total knee arthroplasty.

One of the main problems after total knee arthroplasty is pain in the patellofemoral joint, which in some cases leads to revision surgery. Rotation of the femoral component has a significant influence on the path followed by the patella within the patellofemoral joint. We examined the influence of rotation of the femoral component after total knee arthroplasty on patellar tilt. We retrospectively analysed the radiographs of 48 patients who underwent primary LCS total knee arthroplasty without patella resurfacing and without lateral release. Rotation of the femoral component was determined using Kanekasu's technique and patellar tilt assessment according to Laurin on Merchant's views. This radiographic study confirmed a highly significant correlation between external rotation of the femoral component and a decrease in patellar tilt following TKA. Furthermore, we found a highly significant correlation between pre- and postoperative patellar tilt angle.

Pan-caspase inhibition suppresses polyethylene particle-induced osteolysis.

Particle-induced osteolysis is a major cause of aseptic loosening after total joint replacement. Earlier studies demonstrated apoptotic macrophages, giant cells, fibroblasts and T-lymphocytes in capsules and interface membranes of patients with aseptic hip implant loosening. The aim of the current study was to determine in a murine calvarial model of wear particle-induced osteolysis whether inhibition of apoptosis using the pan-caspase inhibitor BOC-D-FMK reduces aseptic loosening. Healthy 12-week-old male C57BL/6J mice were treated with UHMWPE particles and received a daily peritoneal injection of BOK-D-FMK, respectively only buffer at a dose of 3 mg/kg of body weight for 12 days until sacrifice. Bone resorption was measured by histomorphometry, micro CT (computed tomography) and TRAP-5b serum analysis. Apoptosis was measured using caspase-3 cleaved staining. The results demonstrated that UHMWPE particles induced stronger apoptotic reactions in macrophages and osteoblasts and increased bone resorption in non-specifically treated mice, whereas peritoneal application of BOC-D-FMK significantly counteracted these adverse particle-related effects. We think that in particle-induced osteolysis apoptosis is pathologically increased, and that failure to reduce the quantity of apoptotic bodies leads to an up-regulation of proinflammatory cytokines, which may be responsible for the induction of osteolysis. We showed for the first time in vivo that a reduction in apoptosis leads to a significant reduction in particle-induced osteolysis. Clinically, the apoptotic cascade could become an interesting novel therapeutic target to modulate particle-induced osteolysis.

Extrinsic and intrinsic pathways of apoptosis in aseptic loosening after total hip replacement.

Particle-induced osteolysis is a major cause of aseptic loosening after total joint replacement. The purpose of the current study was to identify various apoptosis-related pathways in the cellular response to wear debris. Fas receptor, BAK and caspase-3 cleaved were evaluated immunohistochemically in capsules and interface membranes from patients with aseptic hip implant loosening. Moreover, we investigated local cellular proliferation, documented by the presence of Ki-67, to evaluate the proportion of apoptosis in relation to the proliferation in the different cells. We detected a strong expression of caspase-3 cleaved, Fas and BAK in macrophages, giant cells and T-lymphocytes. The fibroblasts showed caspase-3 cleaved and BAK, but no Fas staining. Demonstrated by Ki-67 staining, we found increased proliferation of macrophages and fibroblasts. Statistical analysis showed a significant positive correlation (p<0.001) between the above mentioned results and the presence of wear debris. The intensity of apoptosis and proliferation differed, depending on the extent of osteolysis. Overall, four different patterns of immunoreactivity were identified. We think, however, that in particle-induced osteolysis apoptosis is pathologically increased - a phenomenon also seen in other diseases. In these instances, the number and degree of apoptotic reactions are so great that the resulting cell remains cannot be completely removed. This leads to an increased excretion of fibrogenic mediators that could be responsible for increased proliferation of fibroblasts in spite of the increased apoptosis. Moreover, it leads to an increased excretion of cytokines which could be responsible for the activation of osteoclasts.

The density of nociceptive SP- and CGRP-immunopositive nerve fibers in the dura mater lumbalis of rats is enhanced after laminectomy, even after application of autologous fat grafts.

A considerable number of patients complain about pain after lumbar surgery. The spinal dura mater has been debated as a possible source of this pain. However, there is no information if laminectomy influences the nociceptive sensory innervation of the dura. Therefore, we quantitatively evaluated the density of SP- and CGRP-immunopositive nerve fibers in the dura mater lumbalis in an animal model of laminectomy. Twelve adult Lewis rats underwent laminectomy, in six of them the exposed dura was covered by an autologous fat graft. Further six animals without surgical treatment served as controls. Six weeks after surgery, the animals were perfused and the lumbar dura was processed immunohistochemically for the detection of CGRP- and SP-containing nerve fibers. In controls, the peptidergic nerve fibers were found predominantly in the ventral but rarely in the dorsal dura mater lumbalis. After laminectomy, the density of SP- and CGRP-immunopositive neurons significantly increased in ventral as well as in dorsal parts of the dura. Axonal spines could be observed in some cases at the site of laminectomy. The application of autologous fat grafts failed to inhibit the significant increase in the density of peptidergic afferents. Thus, we have provided the first evidence that laminectomies induce an increase in the density of putative nociceptive SP- and CGRP-immunopositive neurons in the lumbar dura mater ascribable to an axonal sprouting of fine nerve fibers. This effect was not prevented by using autologous fat grafts. It is conceivable that the neuronal outgrowth of nociceptive afferents is a cause of low back pain observed after lumbar surgery.

Digital templating in total hip arthroplasty with the Mayo stem.

PATIENTS: In 40 patients undergoing total hip arthroplasty with the Mayo femoral stem we studied how preoperative digital templating corresponded to the actual intraoperative choice of implant size, position, offset and restoration of leg length. RESULTS: The preoperatively planned sizes of the components showed a high rate of coincidence with the sizes used intraoperatively [Intraclass Correlation Coefficient (ICC) 0.661-0.810]. However, the agreements in offset and CCD correction were poor (ICC 0.476, 0.253). This could be statistically attributed to the change in the distance from the medial margin of the stem to the medial margin of the medial femoral cortex and the height of osteotomy. The agreement in leg length correction was moderate (ICC 0.583), which was attributed to the change in the hip rotation center and the height of osteotomy. CONCLUSION: Careful preoperative planning was useful for accurate size choice of the Mayo prosthesis. Factors such as the height of osteotomy and the distance from the medial margin of the stem to the medial margin of the medial femoral cortex in relation to the position of the Mayo stem should be taken into account in order to restore ideal offset and leg length.

Arthroscopic Reconstruction of Intratendinous Lesions of the Supraspinatus Tendon - a Systematic Review. / Die arthroskopische Rekonstruktion der intratendinösen Läsion der Supraspinatussehne ­ ein systematischer Review.

BACKGROUND: Intratendinous lesions of the rotator cuff of the shoulder are frequent and may be a distinct clinical entity. Nevertheless, there are only a few publications which deal specifically with this subject. This study analyses the existing literature for the arthroscopic reconstruction of the intratendinous lesion of the supraspinatus tendon, by means of a systematic review, and identifies relevant research questions for future studies. MATERIAL AND METHODS: In January 2017, a systematic review of the U. S. National Library of Medicine/National Institutes of Health (PubMed) Database and the Cochrane Library was conducted using the PRISMA checklist. The search words were "supraspinatus" and "interstitial"; "supraspinatus", "tear" and "intratendinous"; "supraspinatus" and "concealed". In the course of the review, articles written in English with at least a partial arthroscopic case series dealing with the reconstruction of the supraspinatus tendon were identified and further analysed. RESULTS: Primarily 70 hits could be generated. Five articles met the inclusion criteria and were analysed in detail. The number of arthroscopic cases ranged between 6 and 33. Level of evidence was IV in all studies. The diagnosis of an intratendinous lesion was made by MR imaging when T2/fat-saturated sequences showed an intratendinous high intensity signal without disruption of the bursal or articular layer. Three different concepts were followed in surgical treatment: opening of the intratendinous lesion from the bursal or articular side or by complete resection of the lesion. The reconstruction was performed with suture anchors in all cases. In the majority of cases, an acromioplasty was also performed. The reported clinical results were mostly good. Healing of the tendon was shown by MR imaging in 81.5 to 100% of cases. CONCLUSION: After failure of conservative treatment, symptomatic intratendinous lesions of the supraspinatus tendon can be localised intraoperatively and reconstructed after failure of conservative treatment. The expected results are good in the medium term. The evidence level of the studies analysed was low. Future studies should examine the role of alternative conservative and surgical therapies.

The bra strap incision in the open Latarjet procedure.

BACKGROUND: The anterior deltopectoral approach is the standard approach for performing the open Latarjet procedure. Through the use of a more medial and vertical skin incision, the scar can be cosmetically covered by the bra strap in women. We call this incision the bra strap incision. The intention of this study was (1) to elaborate if the bra strap incision is considered beneficial by female patients, (2) to find reproducible landmarks to indicate how the bra strap incision has to be oriented, and (3) to evaluate preliminary clinical results of patients in whom the bra strap incision was used. METHODS: In 18 patients with a mean follow-up of 21 (range, 12-31) months treated with an open Latarjet procedure through the bra strap incision, the clinical results (scar satisfaction, Constant and Murley score [CMS], and subjective shoulder value [SSV]) were retrospectively analyzed. To assess the typical course of the bra strap, anatomical landmarks were assessed in 100 consecutive female patients as the distance from the bra strap center to (1) the tip of the coracoid process, (2) the superior end of the anterior axillary fold, and (3) the acromioclavicular joint. RESULTS: All (18 of 18) patients stated that they would prefer the bra strap incision if the same procedure had to be performed on the opposite shoulder; 16 women were satisfied with the scar. The mean CMS was 83 (range 64-96) points and the mean SSV was 85 (range, 60-100) %. The mean distances from the bra strap center to the acromioclavicular joint, coracoid tip, and axillary fold were 28 (range, 5-60) mm, 15 (range, 2-17) mm, and 30 (range, 2-55) mm. No combination of distance measures and demographic variable revealed a linear relationship. CONCLUSION: This analysis shows that the bra strap incision appears to be highly welcomed by female patients and does not compromise the clinical outcome, when compared to previously published data. However, even though the typical location of the bra strap can be determined, the large variations in the distances make it more preferable to preoperatively mark the incision for optimal placement. TRIAL REGISTRATION: The study is approved by the Ethical Committee Zurich. (Cantonal Ethical Committee number: ZH-Nr.2017-00891 ).

Polyethylene particle-induced bone resorption in alpha-calcitonin gene-related peptide-deficient mice.

UNLABELLED: This study investigates the impact of alpha-CGRP on bone metabolism after implantation of polyethylene particles. alpha-CGRP knockout mice showed less osteolysis compared with wildtype mice. The local neurogenic microenvironment might be a crucial factor in particle-induced osteolysis. INTRODUCTION: Periprosthetic osteolysis is the major reason for aseptic loosening in joint arthroplasty. This study aimed to investigate the potential impact of alpha-calcitonin gene-related peptide (alpha-CGRP) deficiency on bone metabolism under conditions of polyethylene particle-induced osteolysis. MATERIALS AND METHODS: We used the murine calvarial osteolysis model based on polyethylene particles in 14 C57BL 6 mice and 14 alpha-CGRP-deficient mice divided into four groups of 7 mice each. Groups 1 (C57BL/J 6) and 3 (alpha-CGRP knockout) received sham surgery, and groups 2 (C57BL/J 6) and 4 (alpha-CGRP knockout) were treated with polyethylene particles. Qualitative and quantitative 3D analyses were performed using microCT. In addition, bone resorption was measured within the midline suture by histological examination. The number of osteoclasts was determined by counting the TRACP(+) cells. Calvarial bone was tested for RANKL expression by RT-PCR and immunocytochemistry. RESULTS: Bone resorption was significantly reduced in alpha-CGRP-deficient mice compared with their corresponding wildtype C57BL 6 mice as confirmed by histomorphometric data (p < 0.001) and microCT (p < 0.01). Osteoclast numbers were significantly reduced in group 3 and the particle subgroup compared with group 1 (p < 0.001). We observed a >3-fold increase of basal RANKL mRNA levels within group 1 compared with group 3. Additional low RANKL immunochemistry staining was noted in groups 3 and 4. CONCLUSIONS: In conclusion, alpha-CGRP knockout mice did not show the expected extended osteolysis compared with wildtype mice expressing alpha-CGRP. One of the most reasonable explanations for the observed decrease in osteolysis could be linked to the osteoprotegerin (OPG)/RANK/RANKL system in alpha-CGRP-deficient animals. As a consequence, the fine tuning of osteoclasts mediating resorption in alpha-CGRP-null mice may be deregulated.

Over-expression of p53/BAK in aseptic loosening after total hip replacement.

Particle-induced osteolysis is a major cause of aseptic loosening after total joint replacement. The possible induction of apoptosis has not been addressed in great detail. Thus far, it has been shown that ceramic and polyethylene particles can induce apoptosis of macrophages in vitro. The purpose of this study was to test the hypothesis that wears debris generated from total hip arthroplasty could induce cellular damage and apoptosis in vivo. We therefore determined by immunohistochemical methods if increased expression of p53, an important transcription factor, and BAK and Bcl-2, two important regulators of apoptosis, can be found in interface membranes and capsules of hips with aseptically loose implants. Strongly positive immunohistochemical staining for p53 and BAK was found in peri-implant tissues from patients with aseptic hip implant loosening. Differentiation of various cell types showed that macrophages stained positive for p53 in all capsule and interface specimens. p53 was frequently detected in giant cells. Positive staining of BAK in macrophages and giant cells was seen in all specimens. Some positive reactions were observed in fibroblasts, only two of 19 cases stained for p53 and three cases for BAK within synovial cells. Positive macrophages and giant cells were localized around polyethylene particles. While T-lymphocytes showed a regular BAK-staining, the other leukocytes were negative. Statistical analyses showed significant positive correlations (p < 0.001) between the presence of polyethylene and metal debris and the expression of BAK and p53. Polyethylene particles were surrounded by more positive macrophages and giant cells than were metal particles, indicating that polyethylene debris may be a stronger inductor of cell cycle arrest and apoptosis than metal debris. In this study apoptosis of macrophages, giant cells and T-lymphocytes in capsules and interface membranes of patients with aseptic hip implant loosening has been demonstrated in vivo. It is possible that the apoptotic cascade could evolve as a novel therapeutic target to prevent particle-induced osteolysis.

Titanium serum levels may remain elevated despite hip revision surgery for wear-through of an acetabular component.

A 62-year-old female patient showed radiographic signs of severe linear wear of the acetabular component six years after cementless total hip arthroplasty. This suggested wear-through of the acetabular liner with secondary wear of the titanium shell. At revision surgery wear-through of both the inlay and the acetabular shell were confirmed. Despite meticulous debridement serum titanium levels remained elevated for more than 12 months. Wear-through of a polyethylene acetabular liner with secondary wear of the titanium shell can lead to increased titanium serum levels. Titanium serum levels can remain highly elevated despite revision surgery.