Etiology, Classification, Diagnostics, and Conservative Management of Osteochondral Lesions of the Talus. 2023 Recommendations of the Working Group "Clinical Tissue Regeneration" of the German Society of Orthopedics and Traumatology.

METHODS: Peer-reviewed literature was analyzed regarding different topics relevant to osteochondral lesions of the talus (OLTs) treatment. This process concluded with a statement for each topic reflecting the best scientific evidence available for a particular diagnostic or therapeutic concept, including the grade of recommendation. Besides the scientific evidence, all group members rated the statements to identify possible gaps between literature and current clinical practice. CONCLUSION: In patients with minimal symptoms, OLT progression to ankle osteoarthritis is unlikely. Risk factors for progression are the depth of the lesion on MRI, subchondral cyst formation, and the extent of bone marrow edema. Conservative management is the adaptation of activities to the performance of the ankle joint. A follow-up imaging after 12 months helps not to miss any progression. It is impossible to estimate the probability of success of conservative management from initial symptoms and imaging. Cast immobilization is an option in OLTs in children, with a success rate of approximately 50%, although complete healing, estimated from imaging, is rare. In adults, improvement by conservative management ranges between 45% and 59%. Rest and restrictions for sports activities seem to be more successful than immobilization. Intra-articular injections of hyaluronic acid and platelet-rich plasma can improve pain and functional scores for more than 6 months. If 3 months of conservative management does not improve symptoms, surgery can be recommended.

Impact of polyethylene glenoid cementation technique on cement mantle integrity and stability after cyclic loading: a computed tomography and biomechanical study.

BACKGROUND: There are no generally accepted guidelines for polyethylene (PE) glenoid component cementation techniques. In particular, it is not known whether the backside of a PE glenoid should be fully or partially cemented-or not cemented at all. We hypothesized that cementing techniques would have an impact on cement mantle volume and integrity, as well as biomechanical stability, measured as micromotion under cyclic loading. METHODS: To address our hypothesis, 3 different cementation techniques using a single 2-peg PE glenoid design with polyurethane foam were compared regarding (1) the quality and quantity of the cement mantle and (2) biomechanical stability after cyclic loading in vitro. Eight identically cemented glenoids per group were used. Group A underwent cement application only into the peg holes, group B received additional complete cement mantle application on the backside of the glenoid, and group C received the same treatment as group B but with additional standardized drill holes in the surface of the glenoid bone for extra cement interdigitation. All glenoids underwent cyclic edge loading by 105 cycles according to ASTM F2028-14. Before and after loading, cement mantle evaluation was performed by XtremeCT and biomechanical strength and loosening were evaluated by measuring the relative motion of the implants. RESULTS: The cement mantle at the back of the implant was incomplete in group A as compared with groups B and C, in which the complete PE backside was covered with a homogeneous cement mantle. The cement mantle was thickest in group C, followed by group B (P = .006) and group A (P < .001). We did not detect any breakage of the cement mantle in any of the 3 groups after testing. Primary stability during cyclic loading was similar in all groups after the "running-in" phase (up to 4000 cycles). Gross loosening did not occur in any implant. CONCLUSIONS: Coverage of the PE glenoid with cement was reproducible in the fully cemented groups (ie, groups B and C) as compared with relevant cement defects in group A. The addition of cement to the back of the PE glenoid and additional drill holes in the glenoid surface did not improve primary stability in the tested setting.

Instability of the proximal radioulnar joint in Monteggia fractures-an experimental study.

BACKGROUND: A Monteggia fracture is defined as a fracture of the proximal ulna combined with a luxation of the radial head. The aim of the present work is to evaluate the extent of instability of the radius head in the proximal radioulnar joint (PRUJ) as a function of the severity of elbow fracture and ligamentous injury in an experimental biomechanical approach. METHODS: Eight fresh-frozen cadaver arms were used. All soft tissues were removed except for the ligamentous structures of the PRUJ and forearm. A tensile force of 40 N was exerted laterally, anteriorly or posteriorly onto the proximal radius. The dislocation in the PRUJ was photometrically recorded and measured by two independent examiners. After manual dissection of the ligamentous structures up to the interosseous membrane, the instability was documented and subsequently measured. The following dissection levels were differentiated: intact ligamentous structures, dissection of annular ligament, oblique cord and proximal third of interosseous membrane. RESULTS: An anterior instability remains relatively constant until the proximal third of the interosseous membrane is dissected. The radial head already dislocates relevantly in the posterior direction after dissection of the annular ligament with an additional considerable stability anteriorly and laterally. Subsequently, the posterior instability increases less pronouncedly in regard of distal resected structures. The lateral instability increases constantly during the progressing resection of the ligamentous structures. CONCLUSION: On the one hand, a complete healing of the ligament injury after functional treatment is hardly conceivable with ligamentary damage up to the level of the proximal interosseous membrane. A remaining instability of the proximal radius could therefore be a possible cause for the unsatisfactory clinical results after certain Monteggia fractures. On the other hand, the present study may give a possible explanation (i.e. early dorsal radius head dislocation after dissection of annular ligament) why the Bado II injury is the most frequent type of Monteggia fractures.

Two-step stem cell therapy improves bone regeneration compared to concentrated bone marrow therapy.

Adult stem cells are a promising tool to positively influence bone regeneration. Concentrated bone marrow therapy entails isolating osteoprogenitor cells during surgery with, however, only low cells yield. Two step stem cell therapy requires an additional harvesting procedure but generates high numbers of progenitor cells that facilitate osteogenic pre-differentiation. To further improve bone regeneration, stem cell therapy can be combined with growth factors from platelet rich plasma (PRP) or its lysate (PL) to potentially fostering vascularization. The aim of this study was to investigate the effects of bone marrow concentrate (BMC), osteogenic pre-differentiation of mesenchymal stromal cells (MSCs), and PL on bone regeneration and vascularization. Bone marrow from four different healthy human donors was used for either generation of BMC or for isolation of MSCs. Seventy-two mice were randomized to six groups (Control, PL, BMC, BMC + PL, pre-differentiated MSCs, pre-differentiated MSCs + PL). The influence of PL, BMC, and pre-differentiated MSCs was investigated systematically in a 2 mm femoral bone defect model. After a 6-week follow-up, the pre-differentiated MSCs + PL group showed the highest bone volume, highest grade of histological defect healing and highest number of bridged defects with measurable biomechanical stiffness. Using expanded and osteogenically pre-differentiated MSCs for treatment of a critical-size bone defect was favorable with regards to bone regeneration compared to treatment with cells from BMC. The addition of PL alone had no significant influence; therefore the role of PL for bone regeneration remains unclear. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1318-1328, 2019.

Elbow arthroscopy in children and adolescents: analysis of outcome and complications.

BACKGROUND: Chondral or osteochondral lesions, post-traumatic contracture and loose bodies of the elbow are often associated with chronic pain, stiffness, repetitive swelling and joint blockages. Therefore, arthroscopy of the elbow is often used in the elderly for the treatment of osteochondral defects or arthrolysis. There are only a few reports and studies about arthroscopic therapy of the elbow in children and adolescents. This study assesses the clinical outcome of arthroscopic therapy in this age group. METHODS: In a retrospective study, children and adolescents who underwent an elbow arthroscopy in the period from 2010 to 2014 were included. The children were evaluated using the validated outcome measures Mayo Elbow Performance Score (MEPS), range of motion, pain on visual analog scale (VAS), Oxford Elbow Score (OES), quick dash and postoperative satisfaction. Furthermore, all complications were analyzed. RESULTS: In total, 27 patients were included. The mean (range) age was 14 (11-17) years, with a follow-up of 45 months. Fourteen (52%) were female and thirteen children (48%) were male. Twenty children had an arthroscopy due to osteochondritis dissecans and seven children for post-traumatic pain and stiffness. The mean (standard deviation) MEPS improved from 65 (15) to 96 (8; p = .005). The OES and quick dash were 93 and 5.4. The mean extension improved from - 15° (± 13.8) to 3° (± 10.2; p < .001). The mean flexion improved from 131° (± 13.4) to 137° (± 9.5; p = .003). Average pain on VAS was postoperative .2 (± .5), and 81.5% of all children had excellent or good results. There were no complications such as damage of nerves or blood vessels observed. CONCLUSION: Elbow arthroscopy is an appropriate and safe treatment option in children and adolescents with good and excellent postoperative results.

Effects of a home-based exercise program on physical capacity and fatigue in patients with low to intermediate risk myelodysplastic syndrome-a pilot study.

INTRODUCTION: Fatigue is a frequent and disabling symptom in myelodysplastic syndromes (MDS). There is evidence for the benefit of exercise on fatigue in haematological malignancies, but clinical trials targeting patients with MDS do not exist. METHODS: A prospective, non-randomized feasibility trial was conducted to assess the safety and efficacy of a home-based exercise intervention in patients with MDS. Exercise schedule contained endurance or strength training in daily turns over 12 weeks. Outcome measures included 6-min walking distance (6-MWD), an ergometer check, strength measurement of lower limb, abdomen and back, quality of life and fatigue. RESULTS: Twenty-one patients (13 male, 8 female) were included. Median age was 66 years (range 29-87). Fifteen patients (71%) continued the program till week 12 (T1), of whom eleven patients met criteria for program completion. There were no adverse events reported due to the intervention. 6-MWD significantly improved from 580m at T0 to 645m at T1 (p<0.05). Fatigue scores did not significantly change over time (MFI: 12.8 vs. 12.3 vs. 11.9; QLQ-C30 fatigue scale: 48.2 vs. 46.7 vs. 47.4). CONCLUSION: These data provide evidence that an unsupervised outpatient exercise program is feasible and can improve physical capacity. Randomized, controlled studies implementing these interventions are warranted.

Core Decompression and Autologous Bone Marrow Concentrate for Treatment of Femoral Head Osteonecrosis: A Randomized Prospective Study.

The aim of this study was to investigate the safety of injection of bone marrow aspirate concentrate during core decompression and to study its clinical (visual analogue scale; Harris-Hip-score) and radiological outcomes (magnetic resonance imaging). In this prospective and randomized clinical trial we evaluated 24 consecutive patients with non-traumatic femoral head necrosis (FHN) during a period of two years after intervention. In vitro analysis of mesenchymal stem cells was performed by evaluating the fibroblast colony forming units (CFU-Fs). Postoperatively, significant decrease in pain associated with a functional benefit lasting was observed. However, there was no difference in the clinical outcome between the two study groups. Over the period of two years there was no significant difference between the head survival rate between both groups. In contrast to that, we could not perceive any significant change in the volume of FHN in both treatment groups related to the longitudinal course after treating. The number of CFU showed a significant increase after centrifugation. This trial could not detect a benefit from the additional injection of bone marrow concentrate with regard to bone regeneration and clinical outcome in the short term.

Influence of scapular tilt on radiographic assessment of the glenoid component after total shoulder arthroplasty: which radiographic landmarks are reliable?

BACKGROUND: Total shoulder arthroplasty has been shown to improve function and to reduce pain in cases of osteoarthritis. To assess loosening of the glenoid component, serial evaluation of frontal plane radiographs of the scapula has been established as the "gold standard." The aim of this study was to evaluate the reliability of different bone landmarks when the scapula is tilted compared with the ideal view. METHODS: Glenoid components were implanted into 6 human cadaveric scapulae. Radiographs were taken exactly anterior-posterior in the frontal plane as well as craniocaudal tilted (±15° and ±30°) and mediolateral tilted (±10° and ±20°). The following landmarks were evaluated: lateral margin of the scapula, medial margin of the scapula, floor of the fossa supraspinatus line, spine of the scapula line, glenoid fossa line, and coracoid base line. RESULTS: In evaluating the inclination of the glenoid component, the medial margin of the scapula had the best intraobserver and interobserver reliability with a variance for each of 2° ± 1° (P < .0001), whereas the lateral margin of the scapula had an acceptable intraobserver and interobserver reliability with a variance of 4° ± 1° and 3° ± 1°. In measuring medial migration, the glenoid fossa line had a significantly lower intraobserver and interobserver reliability than the coracoid base line (each 1 ± 0 mm vs. 3 ± 1 mm and 3 ± 2 mm; P < .0001). CONCLUSION: To assess the inclination of the glenoid component, the medial margin of the scapula has proven best, and the lateral margin of the scapula has acceptable reliability. For measuring medial migration, the coracoid base line has proven acceptable reliability, whereas the glenoid fossa line would be subject to change when osteolysis occurs at the glenoid.

Translation of cell therapy into clinical practice: validation of an application procedure for bone marrow progenitor cells and platelet rich plasma.

PURPOSE: Tissue regeneration can be improved by local application of autologous bone marrow derived progenitor cells (BMSC) and platelet rich plasma (PRP). However, there is a lack of standardized application procedures for clinical use. Therefore, a technique in accordance with the guidelines for advanced therapies medical products of the European Medicine Agency was developed and established. METHODS: In detail, a process for the isolation and formulation of autologous bone marrow cells (BMC) and PRP in a clinical setting was validated. To investigate the influence of storage time and temperature on gel formation and gel stability, different concentrations of BMC were stored with and without additional platelets, thrombin and fibrinogen and analyzed over a period of 28 days. In addition, cell vitality using a live-dead staining and migration ability of human mesenchymal stem cells (hMSC) in the gel clot was investigated. RESULTS: For an optimized stable gel clot, human BMC and PRP should be combined with 10% to 20% fibrinogen (9 mg/mL to 18 mg/mL) and 5% to 20% thrombin (25 I.E. to 100 I.E.). Both freshly prepared and stored cells for 1 to 7 days had a stable consistence over 28 days at 37°C. Different platelet concentrations did not influence gel clot formation. The ratio of living cells did not decrease significantly over the observation period of 5 days in the live-dead staining. CONCLUSIONS: The study identified an optimal gel texture for local application of BMC and PRP. Seeded hMSC could migrate therein and were able to survive to initiate a healing cascade.

Motion patterns in activities of daily living: 3- year longitudinal follow-up after total shoulder arthroplasty using an optical 3D motion analysis system.

BACKGROUND: Total shoulder arthroplasty (TSA) can improve function in osteoarthritic shoulders, but the ability to perform activities of daily living (ADLs) can still remain impaired. Routinely, shoulder surgeons measure range of motion (ROM) using a goniometer. Objective data are limited, however, concerning functional three-dimensional changes in ROM in ADLs after TSA in patients with degenerative glenohumeral osteoarthritis. METHODS: This study included ten consecutive patients, who received TSA for primary glenohumeral osteoarthritis. The patients were examined the day before, 6 months, and 3 years after shoulder replacement as well. We compared them with a control group (n = 10) without any shoulder pathology and measured shoulder movement by 3D motion analysis using a novel 3 D model. The measurement included static maximum values, the ability to perform and the ROM of the ADLs "combing the hair", "washing the opposite armpit", "tying an apron", and "taking a book from a shelf". RESULTS: Six months after surgery, almost all TSA patients were able to perform the four ADLs (3 out of 40 tasks could not be performed by the 10 patients); 3 years postoperatively all patients were able to carry out all ADLs (40 out of 40 tasks possible). In performing the ADLs, comparison of the pre- with the 6-month and 3-year postoperative status of the TSA group showed that the subjects did not fully use the available maximum flexion/extension ROM in performing the four ADLs. The ROM used for flexion/extension did not change significantly (preoperatively 135°-0° -34° vs. 3 years postoperatively 131° -0° -53°). For abduction/adduction, ROM improved significantly from 33°-0° -27° preoperatively to 76° -0° -35° postoperatively. Compared to the controls (118°) the TSA group used less ROM for abduction to perform the four ADLs 3 years postoperatively. CONCLUSION: TSA improves the ability to perform ADL and the individual ROM in ADLs in patients with degenerative glenohumeral osteoarthritis over the course of 3 years. However, TSA patients do not use their maximum available abduction ROM in performing ADLs. This is not related to limitations in active ROM, but rather may be caused by pathologic motion patterns, impaired proprioception or both.

How does reverse shoulder replacement change the range of motion in activities of daily living in patients with cuff tear arthropathy? A prospective optical 3D motion analysis study.

BACKGROUND: Reverse total shoulder arthroplasty (RSA) can improve function in cuff tear arthropathy (CTA) shoulders, but limited exact data are available about the maximum values in 3D motion analysis, and as to how improvements translate into the normal range of motion (ROM) in activities of daily living (ADLs). METHODS: This study included nine consecutive patients (n = 9) who received RSA for CTA without muscle transfers. We measured shoulder movement by a novel 3D motion analysis using the Heidelberg upper extremity model (HUX) which can eliminate compensatory movements of the scapula, and the trunk. The measurement included active maximum values, and four ADLs. RESULTS: Comparing the pre- to the 1-year postoperative status, RSA was associated with a significant increase in the mean maximum values for active flexion of about 43° (SD ± 31) from 66° to 109° (p = 0.001), for active abduction of about 37° (SD ± 26) from 57° to 94° (p = 0.001), and for the active adduction of about 28° (SD ± 10) from 5° to 33° (p = 0.002). Comparing the preoperative to the postoperative ROM in the ADLs in flexion/extension, ROM improved significantly in all ADLs, in abduction/adduction in three of four ADLs. No significant changes were observed in internal/external rotation in any ADLs. CONCLUSION: RSA improves the active maximum ROM for flexion, abduction, and adduction. The patients are able to take advantage of this ROM increase in ADLs in flexion and in most ADL in abduction, but only in trend in internal and external rotation.

3D motion capture using the HUX model for monitoring functional changes with arthroplasty in patients with degenerative osteoarthritis.

BACKGROUND: Although shoulder hemiarthroplasty (SHA) can improve function in osteoarthritic shoulders, the ability to perform activities of daily living (ADL) may remain impaired. Shoulder surgeons routinely measure parameters such as range of motion, pain, satisfaction and strength. A common subjective assessment of ADL is part of the Constant Score (CS). However, there is limited objective evidence on whether or not shoulder hemiarthroplasty can restore normal range of motion (ROM) in ADL. METHODS: The study included eight consecutive patients (n=8; seven women, one man), who underwent SHA for glenohumeral osteoarthritis. The patients were examined the day before, as well as 6 months and 3 years after shoulder replacement. They were compared with a control group with no shoulder pathology, and shoulder movement was measured with 3D motion analysis using the "Heidelberg Upper Extremity" (HUX) model. Measurements included static maximum values and four ADL. RESULTS: Comparing the preoperative to the 3-year postoperative static maximum values, there were significant improvements for abduction from 50.5° (SD ± 3 2.4°) to 72.4° (SD ± 38.2°; p=0.031), for adduction from 6.2° (SD ± 7.7°) to 66.7° (SD ± 18.0°; p=0.008), for external rotation from 15.1° (SD ± 27.9°) to 50.9° (SD ± 27.3°; p=0.031), and for internal rotation from -0.6° (SD ± 3.9°) to 35.8° (SD ± 28.2°; p=0.031). There was a trend of improvement for flexion from 105.8° (SD ± 45.7°) to 161.9° (SD ± 78.2°; p=0.094) and for extension from 20.6° (SD ± 17.0°) to 28.0° (SD ± 12.5°; p=0.313). The comparison of the 3-year postoperative ROM between the SHA group and controls showed significant differences in abduction; 3-year postoperative SHA ROM 72.4° (SD ± 38.2°) vs. 113.5° (SD ± 29.7°) among controls (p=0.029). There were no significant differences compared to the control group in adduction, flexion/extension and rotation 3 years after SHA surgery. In performing the ADL, the pre- to the 6-month and 3-year postoperative status of the SHA group resulted in a significant increase in ROM in all planes (p<0.05). Comparing the preoperative to the 3-year postoperative ROM used in ADL, there was an improvement in the flexion/extension plane, showing an improvement trend from preoperative 85°-0°-25° to postoperative 127°-0°-38° (p=0.063). In comparison, controls used a significantly greater ROM during ADL with mean flexion/extension of 139°-0°-63° (p=0.028). For the abduction/adduction plane, ROM improved significantly from preoperative 25°-0°-19° to postoperative 78°-0°-60° (p=0.031). In comparison to controls with abduction/adduction of 118°-0°-37° 3 years postoperative, the SHA group also used significantly less ROM in the abduction/adduction plane (p=0.028). CONCLUSION: While SHA improves ROM in ADL in patients with degenerative glenohumeral osteoarthritis, it does not restore the full ROM available for performing ADL compared to controls. 3D motion analysis with the HUX model is an appropriate measurement system to detect surgery-related changes in shoulder arthroplasty.

Bilateral idiopathic osteonecrosis of the major tubercle of the humerus.

UNLABELLED: Bilateral osteonecrosis of the tuberculum majus has not been reported in the literature. A case of bilateral avascular necrosis of the tuberculum majus is presented associated with smoking and occasional alcohol consumption as risk factors, which was successfully treated with non-operative treatment. LEVEL OF EVIDENCE: Case report, Level V.

Results of cemented total shoulder replacement with a minimum follow-up of ten years.

BACKGROUND: The purpose of this study was to assess the clinical and radiographic long-term outcomes of patients treated with a third-generation cemented total shoulder replacement and followed for at least ten years. METHODS: The results of thirty-nine arthroplasties were analyzed clinically with use of the Constant score and on radiographs in two projections, with special regard to glenoid component loosening, at a mean of eleven years (range, ten to fifteen years) postoperatively. RESULTS: The mean Constant score was 27 points (range, 11 to 54 points) preoperatively and 61 points (range, 21 to 86 points) postoperatively (p < 0.0001). Mean shoulder flexion increased from 84° (range, 40° to 150°) preoperatively to 133° (range, 40° to 180°) postoperatively; mean abduction, from 77° (range, 40° to 110°) to 123° (range, 40° to 180°); and mean external rotation, from 11° (range, -20° to 40°) to 35° (range, 0° to 60°). No humeral components but 36% of the glenoid components were radiographically loose at the time of follow-up. Kaplan-Meier survivorship of the glenoid component was 100% after thirteen years with revision as the end point, whereas survivorship with radiographic loosening as the end point was only 48% after thirteen years. We found no correlation between glenoid loosening on radiographs and clinical findings such as the Constant score. Cranial migration of the humerus was seen in 69% of the cases. CONCLUSIONS: With the implants, cementation, and surgical technique utilized in this group of patients with primary glenohumeral osteoarthritis, radiographic loosening of the glenoid component and rotator cuff deficiency were very common at the ten to fifteen-year review. The follow-up was not long enough to fully identify the clinical sequelae of these findings.

Proprioception 3 years after shoulder arthroplasty in 3D motion analysis: a prospective study.

BACKGROUND: This prospective study evaluated the development of proprioception over the course of 3 years after shoulder arthroplasty. METHODS: Twenty-one patients were enrolled who underwent total shoulder arthroplasty (n = 10) or hemiarthroplasty (HEMI) (n = 11) for shoulder osteoarthritis. All patients were examined 1 day before the operation, 6 months and 3 years after surgery in a motion analysis study with an active angle-reproduction (AAR) test. RESULTS: Overall proprioception measured by the AAR deteriorated significantly 3 years after surgery [from 6.6° (SD 3.1) to 10.3° (SD 5.7); p = 0.017] and was significantly worse than in the control group [10.3° (SD 5.7) vs. 7.8° (SD 2.3); p = 0.030). In the HEMI subgroup, 3 years after shoulder replacement, there is a significant deterioration of proprioception at 30° of external rotation [from 3.1° (SD 3.5) to 12.8° (SD 10.7); p = 0.031]. On average, in the TSA subgroup proprioception deteriorated from 7.1° (SD 3.1) to 8.6° (SD 1.4) and in the HEMI subgroup from 6.1° (SD 2.1) to 12.4° (SD 8.3). The comparison of postoperative impairment of proprioception between the TSA and HEMI subgroup showed significantly worse proprioception for the HEMI subgroup at 30° of external rotation [9.8° (SD 10.1) vs. 1.6° (SD 6.3) in the TSA group; p = 0.046]. CONCLUSION: In conclusion, proprioception that was measured by an AAR test remained unchanged or deteriorated 3 years after shoulder arthroplasty. The postoperative deterioration of proprioception was more distinctive in HEMI than in TSA group.

Subcutaneous emphysema of the upper extremity after elbow arthroscopy.

Subcutaneous emphysema of the upper extremity is rare. Crepitation on physical examination and visible gas on radiographs raise the concern of gas gangrene due to gas-producing bacteria. Rapid establishment of a differential diagnosis is necessary to initiate proper treatment. We present a case of subcutaneous emphysema after elbow arthroscopy caused by a noninfectious genesis. A 59-year-old woman with loose bodies in her left elbow due to mild degenerative joint disease and restricted range of motion was offered an elbow arthroscopy with removal of loose bodies and arthrolysis. Postoperatively, the elbow was actively put alternatively in maximum extension and flexion. On the first postoperative day, rapidly ascending swelling and subcutaneous crepitation starting from the hand to the forearm were noted. There was no clinical evidence of infection. Radiographs showed subcutaneous air. Frequent blood tests and clinical evaluation ruled out a potentially life-threatening bacterial infection, and the signs resolved after 1 week without surgical treatment. Presumably, the intensive postoperative range-of-motion exercises led to a sucking in of air into the wound during each movement. This case illustrates that it is important to differentiate nonbacterial from bacterial causes of soft-tissue gas formation to initiate the appropriate treatment.

Prospective randomised comparison of arthroscopic versus mini-open rotator cuff repair of the supraspinatus tendon.

PURPOSE: The aim of the study was to evaluate whether arthroscopic (ASC) repair of rotator cuff ruptures causes less postoperative pain and better range of motion (ROM) in the early postoperative period than a mini-open (MO) technique. METHODS: Inclusion criteria were a rupture of the supraspinatus tendon with retraction with a maximum to the apex of the humeral head and minor fatty degeneration and atrophy of the muscle. Each group (n = 17) had similar demographics and preoperative magnetic resonance imaging (MRI) findings (mean age 60.1 years, SD 8.8, range 43-71). The ASC group underwent double-row repair with resorbable anchors; the MO group received a transosseous repair. The postoperative rehabilitation was standardised and equivalent in both groups. RESULTS: In the first week fewer nonsteroidal anti-inflammatory drug (NSAID) tablets were needed in the ASC group. Pain scores on the visual analogue scale were similar in the first three weeks; however, from week four to eight the MO group had less pain (p < 0.05). After six months, the Constant-Murley score and the ROM improved significantly (p < 0.05) in both groups without differences between the groups. Postoperative MRI revealed in three of 16 patients a discontinuity of the tendon in both groups; in the ASC group there were more patients (n = 9) with a thinning of the tendon compared to the MO group (n = 6). CONCLUSIONS: There was less use of NSAIDs in the first postoperative week in the ASC group, indirectly indicating less pain, but higher pain scores in the later course (weeks four to eight) compared to the MO group. ROM, MRI findings and the scores were similar after six months, demonstrating that both techniques are equivalent regarding the outcome in this period.

What is the role of intra-operative fluoroscopic measurements to determine tibial tunnel placement in anatomical anterior cruciate ligament reconstruction?

The hypothesis for this study was that intra-operative fluoroscopic measurements can be used to determine tibial tunnel placement during anatomic anterior cruciate ligament (ACL) reconstruction. The anteromedial (AM) and posterolateral (PL) bundle insertion sites were marked with a thermal device and measured in a consecutive cohort of 67 patients undergoing anatomical ACL reconstruction. For double bundle reconstruction, guide pins were passed in the center of the AM and PL tibial footprints. For single bundle (SB) reconstruction a guide wire was placed between the center of AM and PL footprints. Subsequently, the position of the centers of the AM and PL insertion sites were measured on standardized lateral intra-operative fluoroscopic images. The center for the AM bundle was found to be at 31% (range 20-42%) of the AP distance on the medial joint line and at 35% (range 23-42%) of the AP distance on the Amis and Jakob line. The center of the PL bundle was at 48% (range 37-59%) of the AP distance on the medial joint line and 48% (range 39-58%) of the AP distance on the Amis and Jakob line. The center of the tibial tunnel in the SB group (n = 15) was at 42 and 41% in relation to the medial joint line and the Amis and Jakob line, respectively. Because a significant anatomic variation exists between patients, the decision with respect to tunnel placement should not be merely based on intra-operative fluoroscopic images.

Chondrogenic pre-induction of human mesenchymal stem cells on beta-TCP: enhanced bone quality by endochondral heterotopic bone formation.

New techniques to heal bone defects include the combination of bone substitute materials with mesenchymal stem cells (MSC). To find solutions not hampered by low material resorbability or high donor variability of human MSC, the potency of such composites is usually evaluated by heterotopic bone formation assays in immunocompromised animals. The aim of this study was to investigate whether resorbable phase-pure beta-tricalcium-phosphate (beta-TCP) could support heterotopic bone formation by MSC comparable to partially resorbable hydroxyapatite/tricalcium-phosphate (HA/TCP). Furthermore, in light of disappointing results with osteogenic in vitro priming of MSC, we tested whether chondrogenic pre-induction of constructs may allow for enhanced bone formation by triggering the endochondral pathway. beta-TCP granules of three different sizes and HA/TCP were seeded with MSC and transplanted subcutaneously into immunocompromised mice either immediately or after a chondrogenic pre-induction for 6 weeks. After 8 weeks, explants were analysed by histology. beta-TCP seeded with unprimed MSC revealed intramembranous bone formation without haematopoietic marrow with 3.8-fold more bone formed with granules smaller than 0.7 mm than with 0.7-1.4mm particles (p< or =0.018). Chondrogenic pre-induction of beta-TCP/MSC composites resulted in collagen type II and proteoglycan-rich cartilage-like tissue which, after transplantation, underwent endochondral ossification, yielding ectopic bone produced by human cells while haematopoietic marrow was derived from the mouse. Transdifferentiation of MSC-derived chondrocytes to osteoblasts or direct osteogenesis of cartilage-resident MSC is postulated to explain the human origin of new bone. In conclusion, beta-TCP was significantly more osteo-permissive (p=0.004) than HA/TCP for human MSC, and chondrogenic priming of beta-TCP/MSC represented a superior approach capable of supporting full bone formation, including marrow organization.