Medial patellofemoral ligament reconstruction fails to correct mild patella alta in cases of patellofemoral instability-a case-control study.

PURPOSE: Medial patellofemoral ligament reconstruction (MPFL-R) is the gold standard in patella soft tissue surgery for patellofemoral instability. Although claimed, recent reports indicate that MPFL-R may fail to distalize the patella in mild cases of patella alta. The present study is a retrospective case-control study to compare radiographic patella height between MPFL-R and historical Insall's proximal realignment (IPR) pre- and post-operatively with respect to distalization and assess redislocation rates at a mid-term follow-up. METHODS: Sixty-four patients were age/sex matched (1:1), yielding 32 patients for group 1 MPFL-R (cases) and 32 patients for group 2 IPR (controls). Insall-Salvati, Blackburne-Peel and Caton-Deschamps indices were analyzed for differences pre- and post-operatively. An additional inter-rater reliability analysis was performed by means of intra-class correlation (ICC). Redislocation rates were considered as treatment failures in this study. RESULTS: ICC was excellent for all three patella indices. MPFL-R failed to show significant differences if compared to IPR with respect to distalization in mild stages of patella alta. Moreover, redislocation rates significantly favored MPFL-R (3.1%) over IPR (12.5%; p < 0.0001). CONCLUSIONS: MPFL-R has become a popular option to restore native patellofemoral biomechanics after ligament rupture. However, the procedure's potential to correct concomitant patella alta should not be overestimated and indications considered carefully.

Transfusions increase complications and infections after hip and knee arthroplasty: An analysis of 2760 cases.

BACKGROUND: Knee and hip replacement surgery are still the mainstay therapy for osteoarthritis. In spite of the improvement of techniques and implants, anemia is a relatively common complication, with transfusion rates of up to 23% in some centers. OBJECTIVE: The purpose of the study was to determine a correlation of transfusions to complications including infection since this topic is still being debated or even disputed in the literature. METHODS: This is a level III, single center retrospective observational cohort study of 2760 unilateral primary knee and hip replacements. Preoperative assessment, the number of transfusions and the occurrence of complications were collected and the correlations were analyzed using analysis of variance and logistic regression. RESULTS: Fifteen percent of all patients developed at least one complication. Transfusion rate was 9%. Risk factors for receiving a transfusion were female gender, hip replacement, American Society of Anesthesiologists' Score (ASA) > III, history of myocardial infarction, chronic cardiac disease, diabetes mellitus, chronic kidney disease, and length of surgery. The risk factors for developing a complication were: ASA score, presence of chronic renal insufficiency, and transfusion during hospital stay. Transfusion increases the risk of complications and infection rate. Complication rate with transfusion was 34.7% and without transfusion 13.2%. Infection rate without transfusion was 0.4% and with transfusion 2.82%. CONCLUSIONS: The complication rate is higher in transfused patients. The number of complications rises linearly with the number of transfusions. Infection rate is also higher after a transfusion. Efforts should be made to reduce the transfusion rate.

Cartilage Surgery in Overweight Patients: Clinical and MRI Results after the Autologous Matrix-Induced Chondrogenesis Procedure.

Modern orthopaedic surgery provides a variety of techniques for cartilage repair. The Autologous Matrix-Induced Chondrogenesis (AMIC) procedure is a single-step technique with a collagen I/III scaffold for the treatment of full-thickness cartilage lesions. The aim of the study was to analyze the outcome of the AMIC procedure in overweight patients with knee cartilage defects. Overweight patients treated with AMIC surgery were followed up by clinical and MRI examination. 9 patients with a cartilage defect of the knee with a mean lesion size of 2.1 ± 1.2 cm2 and an average body mass index (BMI) of 29.3 were available for the follow-up. The Lysholm Score was significantly improved by the AMIC procedure (38 to 67, p ≤ 0.008). The VAS Score was significantly lower after the procedure (9 to 3, p ≤ 0.018). In the postoperative MOCART Scale, the scaffold reached defect covering of 80%. However, 2 patients had to be revised due to persisting knee pain. The AMIC procedure enhances pain reduction and gain of knee function for cartilage defects of overweight patients. However, in cases of an increased BMI, the patient had to be informed that success rate is reduced despite good defect covering.

Computer-aided planning with exact implementation into surgical technique in TKA is as accurate as intraoperative navigation.

BACKGROUND: Exact positioning of implants and accuracy of alignment are important parameters to provide an long survivorship of endoprostheses after total knee arthroplasty. It was suggested that an alignment within 3∘ from centerline provides the best long-term survivorship of TKA. Therefore, computer-assisted navigation became more important in TKAs. Another tool to improve the accuracy in TKA is the preoperative planning software. OBJECTIVE: Main goal was to determine if advantages of an intraoperative navigation system during TKA can be reached by an exact implementation of a preoperative computer-aided planning. METHODS: Based on all patients (n= 100) underwent primarily TKA in 2015 and 2016 two groups were declared: (1) conventionally operated TKA without navigation system and (2) operation with an optical navigation system. Data on age, sex, date, operative time, severe complications and preoperative vs. postoperative alignment were collected retrospectively. RESULTS: The two groups do not differ in postoperative alignment and frequency of outliers. Furthermore, there was no difference referring to complications and the length of stay in hospital, but operative time was prolonged in the navigation-assisted group. CONCLUSIONS: It can be stated that conventional surgical techniques in TKA are as accurate as navigated ones if an exact preoperative computer aided planning is implemented during surgery.

Patient-specific instruments' routine use over conventional total knee arthroplasty remains inconclusive: Analysis of 961 cases.

BACKGROUND: An increasing demand for total knee arthroplasty (TKA) has pushed innovations in the industry and created a promising new technique called patient specific instruments (PSI). Early reports had promising results such as reducing operative time, cost, and improved alignment. More recent reports are conflicting. OBJECTIVE: We aimed to evaluate bleeding, operative time, complication rates, and in-hospital stay. METHODS: A monocentric retrospective analysis was performed on a total of 961 patients that met inclusion criteria. Four different TKA Systems, two of which were performed using conventional instrumentation (CI) (n= 768) and two with PSI (n= 193) were trialed under the same conditions by three senior surgeons. Operative time, complications, bleeding, range of motion, and length of stay were analyzed. RESULTS: There was no difference in operative time (p= 0.991) and length of hospital stay (p= 0.371) between PSI and CI approaches. Complication rates were lower in the PSI group. CI patients showed less non-compensated blood loss (p< 0.001) but required more transfusions (5.8% vs. 1.5%, p= 0.014). CONCLUSIONS: There was no difference in duration of surgery, length of stay, and total blood loss when performing TKA with PSI or CI. There were fewer complications in the PSI group. It remains debatable whether these findings justify routine use of PSI in TKA.

School sport-associated injuries in adolescents: A single center experience.

BACKGROUND: Each year, on average 1.26 million students face physical injuries at German schools and universities. Implementation of systematic prevention programs against school-associated injuries in adolescents is poor. Part of the reason might be a lack of data on nature and frequency of common school-associated injuries. OBJECTIVE: The aim of this study was to obtain qualitative and quantitative data that might help to develop prevention or protection strategies against sport-associated injuries at school. METHODS: A retrospective analysis was conducted on all patients between the ages of 10 and 16 years admitted from January 1st, 2009 to December 31st, 2013 to the emergency room of an academic teaching hospital for school-associated injuries (n= 901). For injuries associated with school sports, time of injury, type of sports and injured body region were analyzed. RESULTS: A significant part of school-associated injuries occurred in school sports (55.7%). The frequency of school sport-associated injuries per school day did not differ between months or seasons of the school year. Most injuries occurred between the ages of thirteen to fifteen. Ball sports were associated with 41% of all sport-associated injuries, particularly with soccer (22%). Distal extremities like hands (38.4%) and feet/ankle (30.3%) were predominantly injured, but only 5% of cases needed surgery. CONCLUSIONS: Most school-associated injuries occur in school sport, particularly with ball sports. Mostly, distal extremities were injured. Implementation of systematic prevention strategies for a reduction in finger injuries should be subject of future research.

Deepening trochleoplasty combined with balanced medial patellofemoral ligament reconstruction for an adequate graft tensioning.

AIM: To evaluate our modified deepening trochleoplasty combined with a balanced medial patellofemoral ligament (MPFL) reconstruction for soft tissue alignement. METHODS: Thirty-three knees with with recurrent patellar dislocations and a trochlear dysplasia in 30 patients (m/f = 12/21, mean age 24 ± 9 years) underwent a combination of a modified deepening trochleoplasty and a balanced MPFL reconstruction for a medial soft tissue alignement. After a mean follow-up period of 29 ± 23 mo, patients' return to sports, possible complications as well as the clinical outcomes using the Kujala, International Knee Documentation Committee (IKDC) and Lysholm scoring were evaluated. Moreover, patients' satisfaction with the general outcome, the cosmetic outcome, the pre- and postoperative pain and a potential avoidance behaviour were assessed with additional standardized questionnaires which also included different visual analog scales. RESULTS: There were no signs of a persistent instability. The Kujala score improved from a mean of 64 ± 16 points to 94 ± 9 points, the Lysholm score improved from a mean of 63 ± 17 to 95 ± 6 points and the IKDC score from 58 ± 11 to 85 ± 12 points, P < 0.0001, respectively. The assessment of pain using a visual analog scale showed a significant pain reduction from a mean of 4.8 ± 2.0 to 1.3 ± 3.4 points (P < 0.0001). Two of 26 cases (92%) who were engaged in regular physical activity before surgery did not return to full sporting activities. One patient felt that his sport was too risky for his knee and reported an ongoing avoidance behaviour. The other patient preferred to wait for surgery of her contralateral knee. Of the eight patients who were not engaged in sporting activities before surgery, three started regular sporting activities after surgery. In 31 of the 33 cases (94%), the patients were very satisfied with the clinical outcome of the surgery. Regarding the cosmetic results, no patients felt impaired in their self-confidence and in their clothing decisions. CONCLUSION: Our technique shows a good clinical outcome in terms of the common scorings as well as in terms of pain, return to sports and patient satisfaction.

Testing the feasibility and safety of the Nintendo Wii gaming console in orthopedic rehabilitation: a pilot randomized controlled study.

INTRODUCTION: The Nintendo Wii game console is already used as an additional training device for e.g. neurological wards. Still there are limited data available regarding orthopedic rehabilitation. The authors' objective was to examine whether the Nintendo Wii is an appropriate and safe tool in rehabilitation after orthopedic knee surgery. MATERIAL AND METHODS: A prospective, randomized, controlled study comparing standard physiotherapy vs. standard physiotherapy plus game console training (Wii group) in patients having anterior cruciate ligament (ACL) repair or knee arthroplasty was conducted. The subjects of the Wii group (n = 17; mean age: 54 ±19 years) performed simple knee exercises daily under the supervision of a physiotherapist in addition to the normal rehabilitation program. The patients of the control group (n = 13; 52 ±18 years) were treated with physiotherapy only. The participants of both groups completed a questionnaire including the International Knee Documentation Committee (IKDC) score, the Modified Cincinnati Rating System and the Tegner Lysholm Knee Score prior to the operation, before discharge from hospital and four weeks after treatment. RESULTS: There was no significant difference in the score results between the Wii and the control group (p > 0.05). CONCLUSIONS: We demonstrated that physiotherapy using the Nintendo Wii gaming console after ACL reconstruction and knee arthroplasty does not negatively influence outcome. Because training with the Wii device was highly accepted by patients, we see an opportunity whereby additional training with a gaming console for a longer period of time could lead to even better results, regarding the training motivation and the outcome after orthopedic surgery.

Hip arthroscopy for excision of osteoid osteoma and for the application of a collagen cartilage implant: Case report in a professional athlete, and literature review.

BACKGROUND: Osteoid osteoma is an osteoblastic benign bone tumor usually affecting young adolescents. Intra-articular lesions are not common; usually the diagnosis is delayed. A lot of studies report difficulties and complications in the management of osteoid osteoma of the hip joint using imaging guided techniques or open surgical procedures. Only few published cases have described that it can be treated precisely using hip arthroscopy. Additionally, the use of hip arthroscopy to apply the Chondrofiller®, an acellular collagen matrix for the management of articular cartilage defects of the hip joint, has not yet been described. CASE PRESENTATION: This report presents an osteoid osteoma of the femoral neck. A 20-year-old female professional basketball player presented with pain in the left groin since more than 12 months. On magnetic resonance and computed tomography imaging, an osteoid osteoma was suggested. The lesion was successfully removed using arthroscopy. During surgery, a concomitant grade 4 cartilage lesion on the femoral head was detected. For the treatment of this severe defect we used the Chondrofiller®, which is a new acellular collagen implant for auto-regeneration of articular cartilage. This matrix was filled into the prepared and dried defect using CO2 arthroscopy. After the hardening of the matrix the surgery was finished. The patient was pain free shortly after the operation and returned to sports within 16 weeks. Return to high-performance sports 8 months after surgery was without of any sign of complaints. CONCLUSIONS: This article demonstrates that hip arthroscopy is a valuable tool for biopsy and excision of intra-articular osteoid osteoma affecting the hip joint, as well as for addressing other concomitant pathologies such as a severe synovitis or cartilage defects. CO2 arthroscopy provided good conditions for the drying and filling of the cartilage defect with the Chondrofiller®.

Validation of a German version of the International Hip Outcome Tool (G-iHOT33) according to the COSMIN checklist: how much improvement is clinically relevant?

PURPOSE: The evaluation of the subjective health-related quality of life is especially for young, active patients with hip joint disorders important. The MAHORN study group has recently developed the "International Hip Outcome Tool" (iHOT33), a self-administered patient-reported outcome tool, which includes questions on the patient's symptoms, functional and sports limitations as well as social, emotional, and occupational limitations. The purpose of this study was to adapt and validate a German version of the iHOT33 according to the COSMIN checklist. METHODS: To validate the G-iHOT33, we conducted a prospective multicenter cohort study on patients with hip disorders and a score ≥4 on the modified Tegner Activity Scale. The patients completed the G-iHOT33 questionnaire twice at intervals of at least 2 weeks. In addition, we recorded the Hip Outcome Score (HOS), a modified Tegner Activity Scale (TAS), the EuroQol-5D (EQ5-D), and a subjective assessment of the limitations. Evaluation of psychometric properties was conducted following the COSMIN checklist for validation of health status measurement instruments. The methodical testing for reliability included internal consistency, test-retest reliability, and measurement error. For testing of validity, we analyzed construct validity, hypotheses testing, interpretability, and responsiveness. RESULTS: Between December 2013 and December 2014, eighty-three consecutive patients completed both questionnaires and were available for data analysis. Cronbach's α was 0.97 (95% CI 0.96, 0.99) confirming internal consistency and test-retest reliability of the G-iHOT-33 was high with an ICC = 0.88 (95% CI 0.80, 0.99). All a priori hypotheses were confirmed, further, no floor- or ceiling-effects occurred. The G-iHOT33 showed good responsiveness with a minimal important change (MIC) of 10 points. CONCLUSIONS: The German translation of the iHOT-33 (G-iHOT-33) is a viable tool for the evaluation of active patients with a hip disorder. Following the complete COSMIN checklist, we could prove that G-iHOT33 is a reliable, valid, and responsive PRO measurement tool. We could show that the minimal important change, a change of health condition the patient discerns is 10 points in the G-iHOT33 scale. This is the first study providing results on psychometric properties of the iHOT33 subscales. Level of evidence 1b validating cohort study.

Anatomical study of preganglionic spinal nerve and disc relation at different lumbar levels: Special aspect for microscopic spine surgery.

BACKGROUND: Lumbar microdiscectomy is a widespread popular method of treatment. One major challenge is the spine level dependent different anatomy and the limited sight on the nerve root during the surgical procedure. OBJECTIVE: The aim was to analyze the specific anatomic relation of nerve root, intervertebral disc and intervertebral ganglion under determination of the specific nerve distances. Furthermore the relation between the disc and the corresponding nerve root was evaluated. METHODS: Regular human lumbar spine specimens of body donors were included in the study. Microscopic assisted dissection was performed. The topographical distances between a defined disc measurement point (DP) and the corresponding nerve root shoulder (NS) were measured. The preganglionic distance from the caudal axilla point (AP) of the spinal nerve root and the center point (CG) of the spinal ganglion in the intervertebral foramen were determined. RESULTS: The AP-CG distance increased gradually in the caudal direction from L1 (7.25 ± 2.72 mm right side, 7.30 ± 2.85 mm left side) to a maximum for L5 (16.00 ± 3.39 mm right side, 16.50 ± 3.58 mm left side, p< 0.05). We found a significant reduction for S1 (14.88 ± 3.42 mm right side, 13.83 ± 2.47 mm, p< 0.05). In contrast the DP-AP distances showed a maximum for L1 (12.75 ± 2.78 mm right side, 13.70 ± 3.87 mm left side) with an increasing shortening in the caudal direction and even negative values for S1 (-2.63 ± 3.31 mm right side, -0.83 ± 2.84 mm left side, p< 0.01). CONCLUSION: The topographical anatomy changes each lumbar segment and demands therefore an exact preoperative planning using this specific knowledge to perform a successful microscopic spine surgery. The results of the study support a better understanding of the relevant anatomy and help to reduce incomplete herniated disc removal and to avoid surgical complications.

Combination of autologous chondrocyte implantation (ACI) and osteochondral autograft transfer system (OATS) for surgical repair of larger cartilage defects of the knee joint. A review illustrated by a case report.

OBJECTIVES: Modern orthopaedic surgery provides a variety of techniques for cartilage repair. Despite comprehensive scientific data about the single procedures, there is little experience with the combination of these methods. Inspired by a case from our clinic, we performed a PubMed based literature search about the combination of cartilage restoration principles. MATERIALS AND METHODS: The literature search was performed using the terms: ``mosaicplasty'' OR ``osteochondral transplantation'' OR ``OATS'' AND ``autologous chondrocyte implantation'' OR ``autologous chondrocyte transplantation'' OR ``ACI'' OR ``matrix-associated autologous chondrocyte implantation'' OR ``MACI'' AND ``combination''. Abstracts were revised for relevance to our case. Additionally, we present a case report of the combinatory use of three established techniques. RESULTS: Two relevant publications, both reporting satisfying results concerning postoperative functional outcome, were found. Our results confirm this first encouraging assessment, although statistically valid data and prospective studies are still missing. CONCLUSIONS: The simultaneous use of different techniques for cartilage repair may provide alternative operative solutions for single complex cases, although further studies are required for a general recommendation.

Does intraoperative application of leukocyte-poor platelet-rich plasma during arthroscopy for knee degeneration affect postoperative pain, function and quality of life? A 12-month randomized controlled double-blind trial.

INTRODUCTION: We aimed to identify the effects of intraoperative applied leukocyte-poor platelet-rich plasma (LP-PRP) during knee arthroscopy for degenerative lesions involving pain, function and quality of life. METHODS: We performed a randomized controlled, double-blind trial (RCT) including 58 patients for arthroscopic knee surgery for cartilage or meniscal degeneration with allocation into the LP-PRP (n = 24) or control group (n = 34). During arthroscopy, LP-PRP was injected intra-articular in the intervention group. At baseline, 6 weeks, 6 months and 12 months pain, function, and life quality were assessed. RESULTS: 91 % of enrolled patients were available for 12 months follow-up. Pain was significantly lower in the LP-PRP group (VAS 0.9. vs. 2.3) at 6 (p = 0.008) but not at 12 months (VAS 1.0 vs. 1.6, p = 0.063). LP-PRP application improved the Lysholm Score at 6 (77.5 vs. 65.6, p = 0.033) and 12 months (83.2 vs.70.0, p = 0.007). Assessment of life quality (SF-36) concerning the physical component summary was significantly higher at 6 weeks (33.9 vs. 25.6, p = 0.001) and 6 months (29.9 vs. 27.1, p = 0.027) in the LP-PRP group but equal at 1 year (31.4 vs. 30.1, p = 0.438). CONCLUSIONS: Intraoperative application of LP-PRP may enhance pain reduction and gain of knee function within 6-12 months compared to arthroscopy alone. LEVEL OF EVIDENCE: II, randomized controlled clinical trial with reduced power. CLINICALTRIALS. GOV IDENTIFIER: NCT02189408.

Biomimetic structured surfaces increase primary adhesion capacity of cartilage implants.

BACKGROUND: In cartilage repair, scaffold-assisted single-step techniques are used to improve the cartilage regeneration. Nevertheless, the fixation of cartilage implants represents a challenge in orthopaedics, particularly in the moist conditions that pertain during arthroscopic surgery. Within the animal kingdom a broad range of species has developed working solutions to intermittent adhesion under challenging conditions. Using a top-down approach we identified promising mechanisms for biomimetic transfer OBJECTIVE: The tree-frog adhesive system served as a test case to analyze the adhesion capacity of a polyglycolic acid (PGA) scaffold with and without a structural modification in a bovine articular cartilage defect model. METHODS: To this end, PGA implants were modified with a simplified foot-pad structure and evaluated on femoral articular bovine cartilage lesions. Non-structured PGA scaffolds were used as control. Both implants were pressed on 20 mm × 20 mm full-thickness femoral cartilage defects using a dynamometer. RESULTS: The structured scaffolds showed a higher adhesion capacity on the cartilage defect than the non-structured original scaffolds. CONCLUSIONS: The results suggest that the adhesion ability can be increased by means of biomimetic structured surfaces without the need of additional chemical treatment and thus significantly facilitate primary fixation procedures.

Is the Kinect system suitable for evaluation of the hip joint range of motion and as a screening tool for femoroacetabular impingement (FAI)?

BACKGROUND: In the clinical evaluation of femoroacetabular impingement (FAI), there is a lack of quantitative, reliable and informative assessment methods for the overall functional capability of an individual. OBJECTIVE: We compared clinical and radiological measurements of the hip joint with a new methodology based on the concept of 3-dimensional reachable workspace using Microsoft Kinect. METHODS: We assessed the correlation between the alpha angle of Nötzli on full-length radiographs and the clinical internal rotation. We evaluated the accuracy of joint positions and angles of the hip between the Kinect system and clinical examination including range of motion (ROM). RESULTS: The results of our clinical trial with 24 study participants showed a significant difference between normal internal rotation (> 21°) and reduced internal rotation (⩽ 21°) in comparison to the radiological alpha angle of Nötzli (P=0.026). The acquired reachable Kinect data demonstrated a moderate agreement between the Kinect and clinical examination (correlation coefficients between 0.230 and 0.375). CONCLUSIONS: The findings suggest that a higher grade alpha angle of Nötzli accompanies reduced clinical internal rotation. The Kinect system provides reliable results of hip ROM. However, further test series must be performed for the application of Kinect in the clinical evaluation of FAI.

Arthroscopic fixation of cell free polymer-based cartilage implants with a bioinspired polymer surface on the hip joint: a cadaveric pilot study.

This study investigates the adhesion capacity of a polyglycolic acid- (PGA-) hyaluronan scaffold with a structural modification based on a planar polymer (PM) surface in a cadaver cartilage defect model. Two cadaver specimens were used to serially test multiple chondral matrices. In a cadaver hip model, cell free polymer-based cartilage implants with a planar bioinspired PM surface (PGA-PM-scaffolds) were implanted arthroscopically on 10 mm × 15 mm full-thickness femoral hip cartilage lesions. Unprocessed cartilage implants without a bioinspired PM surface were used as control group. The cartilage implants were fixed without and with the use of fibrin glue on femoral hip cartilage defects. After 50 movement cycles and removal of the distraction, a rearthroscopy was performed to assess the outline attachment and integrity of the scaffold. The fixation techniques without and with fibrin fixation showed marginal differences for outline attachment, area coverage, scaffold integrity, and endpoint fixation after 50 cycles. The PGA-PM-scaffolds with fibrin fixation achieved a higher score in terms of the attachment, integrity, and endpoint fixation than the PGA-scaffold on the cartilage defect. Relating to the outline attachment, area coverage, scaffold integrity, and endpoint fixation, the fixation with PGA-PM-scaffolds accomplished significantly better results compared to the PGA-scaffolds (P = 0.03752, P = 0.03078, P = 0.00512, P = 0.00512). PGA-PM-scaffolds demonstrate increased observed initial fixation strength in cadaver femoral head defects relative to PGA-scaffold, particularly when fibrin glue is used for fixation.

Initial boost release of transforming growth factor-ß3 and chondrogenesis by freeze-dried bioactive polymer scaffolds.

In cartilage regeneration, bio-activated implants are used in stem and progenitor cell-based microfracture cartilage repair procedures. Our aim was to analyze the chondrogenic potential of freeze-dried resorbable polymer-based polyglycolic acid (PGA) scaffolds bio-activated with transforming growth factor-ß3 (TGFB3) on human subchondral mesenchymal progenitor cells known from microfracture. Progenitor cells derived from femur heads were cultured in the presence of freeze-dried TGFB3 in high-density pellet culture and in freeze-dried TGFB3-PGA scaffolds for chondrogenic differentiation. Progenitor cell cultures in PGA scaffolds as well as pellet cultures with and without continuous application of TGFB3 served as controls. Release studies showed that freeze-dried TGFB3-PGA scaffolds facilitate a rapid, initial boost-like release of 71.5% of TGFB3 in the first 10 h. Gene expression analysis and histology showed induction of typical chondrogenic markers like type II collagen and formation of cartilaginous tissue in TGFB3-PGA scaffolds seeded with subchondral progenitor cells and in pellet cultures stimulated with freeze-dried TGFB3. Chondrogenic differentiation in freeze-dried TGFB3-PGA scaffolds was comparable to cultures receiving TGFB3 continuously, while non-stimulated controls did not show chondrogenesis during prolonged culture for 14 days. These results suggest that bio-activated, freeze-dried TGFB3-PGA scaffolds have chondrogenic potential and are a promising tool for stem cell-mediated cartilage regeneration.

Primary synovial chondromatosis of the hip - is arthroscopy sufficient? A review of the literature and a case report.

The purpose of this article was to evaluate the different techniques of operative treatment of primary synovial chondromatosis (PSC) of the hip. We performed a systematic review of literature of PSC and also present one case report about arthroscopic treatment of PSC. Our study compares both established operative procedures, open versus arthroscopic surgery, and shows each advantages and complications. One hundred and forty-seven publications were found in a PubMed literature review searching the terms: "synovial chondromatosis", "synovial osteochondromatosis", "synovial metaplasia" and "hip". All included studies were divided into open surgery or arthroscopic surgery concerning the therapeutic strategy and the corresponding results. We could find a total number of 3 reviews about PSC of the hip relating to operative procedures. One patient presented to our outpatient clinic with PSC. After other pathologies causing hip pain were excluded, the patient underwent hip arthroscopy with excision of the loose bodies and partial synovectomy. Diagnosis of PSC was confirmed by histopathology. The patient was examined before and one year after surgery with the Visual Analogue Scale (VAS) and the Hip Outcome Score (HOS ADL). Resecting PSC by hip arthroscopy is a minor surgical, but demanding procedure with minimal risks, even useful in the treatment of elderly patients with moderate osteoarthritis.

Comparative study of the femoroacetabular impingement (FAI) prevalence in male semiprofessional and amateur soccer players.

INTRODUCTION: Femoroacetabular impingement (FAI) represents a novel approach to the mechanical etiology of hip osteoarthritis. The cam-type femoroacetabular impingement deformity occurs frequently in young male athletes. The aim of our study was to evaluate the prevalence of FAI in male semiprofessional soccer players using clinical examination and magnetic resonance imaging (MRI), compared to amateur soccer players. In MRI, the α angle of Nötzli is determined for quantifying FAI. MATERIALS AND METHODS: According to power analysis, a total of 22 asymptomatic semiprofessional soccer players with a median of 23.3 years of age (range 18-30 years) and 22 male amateur soccer players with a median of 22.5 years of age (control group, range 18-29 years) underwent an MRI to measure the hip α angle of Nötzli. The α angle of the kicking legs of the semiprofessional group and the amateur group were analyzed. The study group was moreover evaluated by the Hip Outcome Score (HOS) and a clinical hip examination including range of motion (ROM) and impingement tests. RESULTS: In the semiprofessional group, 19 soccer players had a right kicking leg and 1 soccer player had a left kicking leg. 2 soccer players kicked with two feet. In the semi-professional group, the mean value of the α angle of the kicking leg (57.3 ± 8.2°) was significantly higher than in the amateur group (51.7 ± 4.8°, P = 0.008). In the semi-professional group, 15 (62.5 %) of 24 kicking legs had an increased α angle >55°, while 5 (27.3 %) kicking legs of the amateur group had an α angle >55°. Five semi professional soccer players had findings in clinical examination, whereof 4 had an increased α angle >55°. No participant of the amateur group showed pathological results in the clinical examination (P = 0.0484). Overall, semiprofessional soccer players had a higher proportion of an increased α angle than the amateur group. CONCLUSIONS: Semiprofessional players have a higher prevalence of an increased α angle in the kicking leg than the amateur group at the same age. The kicking leg is predisposed for FAI.

The role of arthroscopy in patients with persistent hip pain after total hip arthroplasty.

BACKGROUND: Total hip arthroplasty (THA) is a safe and successful procedure for the treatment of osteoarthritis. One of the most common postoperative problems remains persistent hip pain. The arthroscopic evaluation of persistent hip pain following THA can be a valuable diagnostic tool in a select number of patients when carried out by experts in this technique. OBJECTIVE: Indication for arthroscopy was persistent pain after THA. Inclusion criteria were an absence of radiological loosening and a sterile aspiration 6 weeks before arthroscopy. Hip joint function and pain were evaluated pre- and postoperatively using the visual analogue scale (VAS) and the Hip Outcome Score (HOS), which scored the activities of daily living (ADL), and a sports subscale. METHODS: 5 patients (3 female, 2 male) with an average age of 60.2 ± 4.27 years (range 51-72 years) were included in the study. Arthroscopy with biopsy, adhesiolysis and psoas tendon release was performed 21.0 ± 21.97 months (range 6-57 months) after primary hip replacement. RESULTS: Pathological findings were prosthetic joint infection (two cases), impingement between acetabular component and psoas tendon (two cases), adhesions of the periprosthetic tissue (one case). The patients achieved a significant improvement of the Hip Outcome Score (HOS), from an average of 45.6 ± 22.5 (range 14.0-63.1) to 76.5 ± 3.8 (range 41.0-89.4, P=0.016). Evaluation of the VAS showed a significant improvement from a preoperative value of 8.8 ± 0.5 to a postoperative value of 3.4 ± 1.0 (P=0.001). CONCLUSION: Hip arthroscopy provides a minimal-invasive tool for diagnosis and therapy. In cases of persistent pain after THA, standard diagnostic procedures should be utilised. Arthroscopy of a hip post-THA would be highly specialised. As a next step, arthroscopy helps the diagnosis and therapy of persistent pain after THA.