Correlation between Oxford Elbow Score and Single Assessment Numeric Evaluation: Is one simple question enough?

BACKGROUND: The aim of this study is to evaluate the correlation between the Oxford Elbow Score (OES) and Single Assessment Numeric Evaluation (SANE). To date, there has been no study investigating a correlation between this patient-reported outcome measure and SANE. METHODS: Between December 2018 and February 2019, all patients who underwent consultation for elbow pathology and completed the OES and SANE were retrospectively analyzed. Pearson correlation coefficient between the OES and SANE was calculated. Variables, including age, gender, diagnosis, chief complaint for consultation, and pain level on the visual analog scale (VAS), were also collected, and a mixed effects linear regression model was used to identify predictors for higher correlation. RESULTS: One hundred seven consultations of 86 patients were analyzed. The mean SANE and OES were 62.13% and 60.36%, respectively. Both scores correlated highly (r = 0.903). Across the OES domains, the strongest correlation was found between SANE and the OES psychosocial domain (r = 0.885). High correlations were also found between SANE and the OES function (r = 0.847) and OES pain (r = 0.804) domains. All values were statistically significant (P < .001). A moderate inverse correlation was found between SANE and VAS (r = -0.631). Aside from SANE, the VAS was identified as a significant predictor of the OES. CONCLUSION: SANE correlates highly with the OES. It is an easy tool for assessing the condition of the elbow joint, can be obtained without any license or payment restrictions, and should be considered as a worthwhile adjunct to currently used scores.

Monocortical fixation of the coracoid in the Latarjet procedure is significantly weaker than bicortical fixation.

PURPOSE: A crucial step of the Latarjet procedure is the fixation of the coracoid process onto the glenoid. Multiple problems associated with the fixation have been described, including lesions of the suprascapular nerve due to prominence of the screw or bicortical drilling. The purpose of the present study was to evaluate whether monocortical fixation, without perforating the posterior glenoid cortex, would provide sufficient graft stability. METHODS: Coracoid transfer was performed in 14 scapula models (Sawbones®, Composite Scapula, 4th generation). Two groups were assigned: in one group, fixation was achieved with two screws that did not perforate the posterior cortex of the glenoid neck (monocortical fixation), in the other group, fixation was achieved with perforation of the posterior cortex (bicortical fixation). The ultimate failure load and mode of failure were evaluated biomechanically. RESULTS: Monocortical fixation was a significantly weaker construct than bicortical fixation (median failure load 221 N, interquartile range 211-297 vs. median failure load 423 N, interquartile range 273-497; p = 0.017). Failure was either due to a pullout of the screws from the socket or a fracture of the glenoid. There was no significant difference in the mode of failure between the two groups (n.s.). CONCLUSION: Monocortical fixation was significantly weaker than bicortical fixation. However, bicortical drilling and overly long screws may jeopardize the suprascapular nerve. Thus, anatomic knowledge about the safe zone at the posterior rim of the glenoid is crucial. Until further research has evaluated, if the inferior stability is clinically relevant, clinicians should be cautious to use a monocortical fixation technique for the coracoid graft.

[Isolated fracture of the coracoid process in a 14-year-old national water polo player : Case example]. / Isolierte Fraktur des Processus coracoideus bei einem 14-jährigen Wasserballnationalspieler : Fallbeispiel.

BACKGROUND: Isolated fractures of the coracoid process during sporting activities are very rare. There are a few case studies and retrospective studies with low numbers of cases. OBJECTIVE: Presentation of an initially neglected fracture and conservative treatment. METHODS: Case study of a 14-year-old national water polo player with a non-dislocated fracture of the coracoid process and conservative therapy using focused shockwave therapy. RESULT: Return to sports after conservative therapy was after 13 weeks and return to competitive sport after 14 weeks. CONCLUSION: In cases with therapy refractory shoulder pain after trauma and unremarkable native X­ray, extended 3D imaging by magnetic resonance imaging (MRI) or computed tomography (CT) should be done early. Conservative therapy of a non-dislocated fracture in this case showed a good outcome.

[Tendinopathies of the shoulder and elbow]. / Tendinopathien an Schulter und Ellenbogen.

BACKGROUND: Tendinopathies of the shoulder and elbow joint are a common problem. According to the current state of knowledge tendinopathies can be separated into acute and chronic tendinitis as well as degenerative tendinosis. ORIGIN: The causes of tendinopathy can be intrinsic, extrinsic or a combination of both. A false straining or overuse with repetitive microtrauma is often the cause. Particularly affected are tendons of the rotator cuff, the long biceps tendons and lower arm extensors. TREATMENT: Priority is given to conservative appproaches for these disease processes. Following appropriate diagnostics the pain can be reduced and function can be improved by specific training. When conservative treatment is unsuccessful and in the presence of certain indications, a surgical approach should be considered. In these cases a structural damage of the tendon often already exists, which could have resulted from the tendinopathy. The structural damage must be considered as a separate entity and differentiated from the tendinopathy.

The lasso-loop, lasso-mattress and simple-cinch stitch for arthroscopic rotator cuff repair: are there biomechanical differences?

PURPOSE: Various stitching techniques have been described to facilitate arthroscopic repair of rotator cuff tears. The aim of the present study was to compare the biomechanical properties of the lasso-loop, lasso-mattress and simple-cinch stitch for rotator cuff repair. METHODS: Twelve infraspinatus tendons were harvested from sheep and split in half. The tendons were randomized into three different stitch configuration groups for biomechanical testing: lasso-loop, lasso-mattress and simple-cinch stitch. Each specimen was first cyclically loaded on a universal materials testing machine under force control from 5 to 30 N at 0.25 Hz for twenty cycles. Then, each specimen was loaded to failure under displacement control at a rate of 1 mm/s. Cyclic elongation, peak-to-peak displacement and ultimate tensile load were reported as mean ± standard error and compared using one way analysis of variance. The type of failure was recorded. RESULTS: No differences in cyclic elongation (1.31 ± 0.09 mm for the simple-cinch vs. 1.49 ± 0.07 mm for the lasso-mattress vs. 1.61 ± 0.09 mm for the lasso-loop stitch, p = 0.063) or peak-to-peak displacement (0.58 ± 0.04 mm for the simple-cinch, 0.50 ± 0.03 mm for the lasso-mattress and 0.62 ± 0.06 mm for the lasso-loop stitch, p = 0.141) were seen between all tested stitch configurations. In the load-to-failure test, the simple cinch stitch (149.38 ± 11.89 N) and the lasso-mattress (149.38 ± 10.33 N) stitch demonstrated significantly higher ultimate load than the lasso-loop stitch (65.88 ± 4.75 N, p < 0.001). All stitch configurations failed with suture pull out. CONCLUSIONS: The lasso-mattress and the simple-cinch stitch showed similar biomechanical properties with significant higher tensile loads needed for failure than the lasso-loop stitch.

A cadaver study comparing intraoperative methods to analyze lower limb alignment.

BACKGROUND: Conventional intraoperative determination of lower limb alignment is essential for orthopedic surgical treatment. Current methods include the cable, alignment rod, and axis board methods. QUESTION/PURPOSES: Are there differences in accuracy and reliability? What are the individual differences in applicability and radiation exposure? METHODS: Twenty legs from 12 fresh-frozen cadavers were randomly selected. After fixation of the legs, measurements were performed using the cable, alignment rod, and axis board methods. Afterwards, all cadavers were subjected to CT scanning. Intersection of the mechanical leg axis with the tibia plateau was calculated as the percentage of the tibia plateau, beginning at the medial border (0%) and ending at the lateral border (100%). Results are presented as mean ± standard deviation (SD). RESULTS: Compared with CT measurements, differences of the intersection at the tibia plateau were 3.9 ± 8.5% with the cable method, 3.6 ± 7.6% using the alignment rod, and 3.6 ± 9.6% using the axis board. The difference among all measurements was not statistically significant (p = 0.450). The average intersection of the mechanical axis was 43.95 ± 5.15% using the cable method, 43.93 ± 5.49% using the alignment rod, and 43.77 ± 5.92% using the axis board. CT measurements revealed an average intersection of 42.46 ± 5.22%. There was no statistically significant difference among conventional results (p = 0.976). We demonstrated good intraobserver reliability for all three methods (cable method, ICC = 0.97; alignment rod, ICC = 0.95; and axis board, ICC = 0.96). There were no statistically significant differences regarding radiation time (p = 0.349) or dose area product (p = 0.823). CONCLUSIONS: All described measurements demonstrated valid measurement of lower limb alignment. With minimal effort, all three methods present a practical and uncomplicated way to control the mechanical axis.

Conversion of hemi into reverse shoulder arthroplasty: implant design limitations.

PURPOSE: Cranial migration of shoulder hemiarthroplasties due to rotator cuff insufficiency typically requires conversion into a reverse total shoulder arthroplasty. This study was conducted to analyze differences between the height and offset of six implants designed to enable conversion of a hemiarthroplasty into a reverse system. METHODS: Anteroposterior radiographs of 40 shoulders were taken. An image analyzing software was used to simulate the implantation of the hemiprostheses. Then the implant was dissembled, leaving on the stem within the humeral shaft. Finally, the implantation of a reverse system was simulated using the stem in the same position. Values are reported as ∆-height and ∆-offset ± standard deviation. Significance was assumed for P < 0.05. RESULTS: The least decrease in height was determined for Implantcast with 11.6 ± 3.3 mm, followed by DePuy (16 ± 5.7 mm) and the greatest for Tornier with 33 ± 5.3 mm. No significant differences were found among Exactech, Mathys and Zimmer. The largest offset-deviation was calculated for DePuy (-21.7 ± 3.7 mm) and the smallest for Implantcast (-3.3 ± 2.8 mm) and Tornier (1.5 ± 5.7 mm). CONCLUSIONS: Due to the modular stem, the system of Implantcast can be converted in a reverse system with the least changes in height and offset. For the other manufacturers it does not seem possible to convert a hemiprosthesis to a reversed prosthesis without accepting additional tension of the deltoid muscle. Further experimental studies have to analyze the changes in deltoid abduction moments after conversion of a hemi- into a reversed prosthesis.

Laser method for intraoperative evaluation of lower extremity alignment: comparison of a novel technique to CT and a conventional method.

INTRODUCTION: Accurate restoration of mechanical alignment is an important factor in reconstructive surgery of the lower extremity. Conventional intraoperative methods, such as using an electrocautery cable, provide only a momentary evaluation of alignment. In this study, we evaluated a novel technique using a laser emitter, which projected the mechanical axis of the lower extremity, providing continuous intraoperative information on alignment. MATERIALS AND METHODS: Alignment of 16 cadaver lower extremities was measured using the electrocautery cable method, the laser method, and CT scan as the standard measurement. The mechanical axis was defined by a line from the center of the femoral head to the center of the ankle. For simplifying measurements the intersection with the tibial plateau was divided into percentages from the medial border (0 %) to the lateral border (100 %). For using the laser method a laser emitting and laser catching device was developed, which is positioned and centered on the femoral head and the ankle using an image intensifier. By catching the laser on the knee region the actual mechanical axis is marked. RESULTS: The data demonstrated good correlation of the laser method when compared to the cable method (P = 0.44). Comparison of the average mechanical axis between cable method and CT (P = 0.819) and laser method and CT (P = 0.647) did not show a statistically significant difference. Average radiation time in comparison between cable method and laser method showed a statistically significant difference (P = 0.013), with the laser method requiring more radiation time. CONCLUSION: Determination of the mechanical axis during surgery remains a difficult clinical problem. Restoration of alignment is an important prognostic factor for surgical outcome. Based on these data, the laser method represents a simple, yet effective tool for continuous intraoperative evaluation of lower extremity alignment.

Clinical Acuity in the Emergency Department and Injury Severity Determine Hospital Admission of Older Patients with Low Energy Falls: Outcomes from a Prospective Feasibility Study.

BACKGROUND: Low energy falls (LEF) in older adults constitute a relevant cause for emergency department (ED) visits, hospital admission and in-hospital mortality. Patient-reported outcome measures containing information about patients' medical, mental and social health problems might support disposition and therapy decisions. We investigated the value of a tablet-based (self-)assessment in predicting hospital admission and in-hospital mortality. METHODS: Patients 65 years or older, consecutively presenting with LEF to our level I trauma center ED (from November 2020 to March 2021), were eligible for inclusion in this prospective observational study. The primary endpoint was hospital admission; secondary endpoints were in-hospital mortality and the use of the tablet for self-reported assessment. Multivariate logistic regression models were calculated to measure the association between clinical findings and endpoints. RESULTS: Of 618 eligible patients, 201 patients were included. The median age was 82 years (62.7% women). The hospital admission rate was 45.3% (110/201), with an in-hospital mortality rate of 3.6% (4/110). Polypharmacy (odds ratio (OR): 8.48; 95% confidence interval (95%CI) 1.21-59.37, p = 0.03), lower emergency severity index (ESI) scores (OR: 0.33; 95%CI 0.17-0.64, p = 0.001) and increasing injury severity score (ISS) (OR: 1.54; 95%CI 1.32-1.79, p < 0.001) were associated with hospital admission. The Charlson comorbidity index (CCI) was significantly associated with in-hospital mortality (OR: 2.60; 95%CI: 1.17-5.81, p = 0.03). Increasing age (OR: 0.94; 95%CI: 0.89-0.99, p = 0.03) and frailty (OR: 0.71; 95%CI: 0.51-0.99, p = 0.04) were associated with the incapability of tablet use. CONCLUSIONS: The severity of fall-related injuries and the clinical acuity are easily accessible, relevant predictors for hospital admission. Tablet-based (self-)assessment may be feasible and acceptable during ED visits and might help facilitate comprehensive geriatric assessments during ED stay.

Arthroscopic arthrolysis for recalcitrant frozen shoulder: a lateral approach.

PURPOSE: The purpose of this study was to evaluate a new all-arthroscopic technique in the management of recalcitrant globally stiff frozen shoulders. This adopts an initial extra-articular approach followed by intra-articular entry to perform a 360° capsular release. METHODS: Ten patients with global adhesive capsulitis were prospectively evaluated. All patients had not improved after undergoing a minimum of 6 months of physiotherapy, and 5 received intra-articular injections of steroids. The mean age was 47 years (range, 33 to 56 years). Patients were examined preoperatively and postoperatively for range of motion. A Constant score and visual analog scale score for pain were recorded. We described an all-arthroscopic technique by entering the subacromial space laterally and opening the rotator interval from the outside in, followed by a complete 360° capsular release and biceps tenotomy. RESULTS: The mean follow-up was 42 months (range, 18 to 90 months), and the mean Constant score improved from 21 to 72 (P < .01). Preoperative abduction improved from a mean of 40° to 165°, elevation improved from 55° to 175°, and external rotation improved from 6° to 58°. The visual analog scale pain score improved from 7 to 1.6, and all patients reported an excellent outcome after surgery. There were no complications particularly regarding axillary nerve injury, fracture, or infection. CONCLUSIONS: This study shows a combined extra-articular and intra-articular approach that is controlled and anatomic and achieves excellent results that were maintained at the midterm. The technique permits anatomic debridement of the rotator interval, enabling excellent intra-articular access, a circumferential capsular release, and biceps tenotomy. There were no complications, and no manipulations were required, which pose a risk of creating soft-tissue lesions, fractures, or dislocations. We recommend this 360° capsular release technique for releasing globally stiff shoulders where the surgeon is experienced in arthroscopy.

Insufficient bone regenerate after intramedullary femoral lengthening: risk factors and classification system.

BACKGROUND: Control of distraction rate with an intramedullary skeletal kinetic distractor (ISKD) may be problematic and a high distraction rate may result in insufficient bone regenerate. QUESTIONS/PURPOSES: Are distraction problems preventable when using the ISKD, and what are the risk factors for and radiologic types of insufficient bone regenerate during ISKD lengthening? PATIENTS AND METHODS: We analyzed 37 consecutive ISKD femoral lengthening procedures in 35 patients with a mean age 33 ± 11 years and minimum followup of 12 months (average, 27 ± 9 months; range, 12-55 months). The average length gain was 42.8 ± 12.9 mm. RESULTS: Eight patients had problems during distraction: seven had "runaway nails" and one had a nondistracting nail. Insufficient bone regenerate developed in eight patients. Important risk factors were a distraction rate greater than 1.5 mm/day (9.1 times higher risk), age 30 years or older, smoking, and lengthening greater than 4 cm. Less important risk factors identified were creation of the osteotomy at the site of previous trauma or surgery and acute correction of associated deformities. We proposed a radiologic classification for failure of bone regeneration: partial regenerate failure (Type I) or complete failure resulting in a segmental defect subdivided according to a length of 3 cm or less (Type IIa) or greater than 3 cm (Type IIb). CONCLUSIONS: Distraction problems with the ISKD were related mostly to internal malfunction of the lengthening mechanism. A distraction rate greater than 1.5 mm/day should be avoided in femoral intramedullary lengthening. Smoking should be a contraindication for femoral lengthening. LEVEL OF EVIDENCE: Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

The relation between tunnel widening and bone mineral density after anterior cruciate ligament reconstruction: an experimental study in sheep.

PURPOSE: The aim of this study was to analyze the relation between bone mineral density (BMD) and femoral tunnel enlargement (TE) in a previously validated sheep model of soft-tissue anterior cruciate ligament (ACL) reconstruction. METHODS: Thirty sheep underwent ACL reconstruction by use of a soft-tissue graft at the age of 4 months. Graft fixation was achieved with the EndoButton (Smith & Nephew Endoscopy, Andover, MA) and Suture Washer (Smith & Nephew Endoscopy). Six animals were killed at 0, 3, 6, 12, and 24 weeks postoperatively. Each ACL-reconstructed knee was examined both by computed tomography to analyze the bone tunnel cross-sectional area and by dual-energy x-ray absorptiometry to analyze BMD. RESULTS: There was a significant increase in tunnel cross-sectional area. BMD decreased significantly within the first 3 weeks after surgery and increased thereafter. A positive correlation between TE and BMD was found. However, a subgroup analysis showed that there is no influence of BMD on the development of a tunnel widening. CONCLUSIONS: The hypothesis that a TE would be associated with a loss in BMD was not confirmed. Tunnel widening during the first 6 months after ACL reconstruction is not affected by the transient changes in BMD. CLINICAL RELEVANCE: There is no correlation between TE and BMD in an experimental sheep model of ACL reconstruction. Translational investigations will determine whether this is also true in humans.

Distal Biceps Tendon Repair Using a Modified Double-Incision Technique: Patient-Reported Outcomes With 10-Year Follow-up.

BACKGROUND: In the setting of complete distal biceps tendon rupture, surgical repair has become the standard of care to restore optimal elbow function, but the optimal approach and method of tendon fixation are still subjects of debate and have remained controversial for more than half a century. PURPOSE: To evaluate patient-reported long-term outcomes after distal biceps tendon repair using a modified double-incision technique. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: We reviewed primary distal biceps tendon repairs after isolated tendon rupture using the modified muscle-splitting double-incision approach and transosseous suture fixation technique described by Morrey et al (1985), which had been performed at our level 1 trauma center between January 2000 and December 2013. Outcome measures included the subjective elbow value (SEV), the Oxford Elbow Score (OES) with its 3 domains (function, pain, and social-psychological), a self-performed hook test, and the 3-level version of the EuroQoL 5-dimensional instrument (EQ-5D-3L) as a measure of health status. Levels of overall satisfaction were determined by asking whether the patient would consent to the operation again. In addition, patients were asked to report any complications. RESULTS: A total of 30 patients met the inclusion criteria, and 25 patients were available for the survey. Mean age at the time of rupture was 47 years. All patients were male. Mean follow-up was 120 months (range, 57-207 months). The follow-up rate was 83.34%. The following outcome results were obtained: SEV, 88.16% ± 25.18%; OES, 43.80 ± 10.56 out of 48 points; OES Pain, 92.50% ± 23.03%; OES Function, 92.25% ± 22.19%; OES Social-Psychological, 89% ± 23.68%; EQ-5D-3L, 0.93 ± 0.21. All patients described a negative hook test. Patient-reported complications included painless limitation in forearm rotation in 8% of patients (n = 2); reduced flexion and forearm rotation strength with and without pain in 8% (n = 2) and 4% (n = 1), respectively; synostosis after 1 year requiring revision surgery in 4% (n = 1); and transient wrist drop in 4% (n = 1). The overall complication rate was 28% (7/25), and 96% (n = 24) would consent to the operation again. CONCLUSION: Despite the cited approach-related morbidity, we report an excellent patient-reported long-term outcome for the double-incision distal biceps repair technique.

Axillary Artery Dissection and Thrombosis after Closed Proximal Humerus Fracture - a Rare Interdisciplinary Challenge. / Dissektion und Thrombosierung der Arteria axillaris bei geschlossener, proximaler Humerusfraktur ­ eine seltene interdisziplinäre Herausforderung.

BACKGROUND: Proximal humerus fractures account for 4 - 6% of all fractures and are a common result of low-energy trauma in the elderly. Concomitant neurovascular injury of the neighboring axillary artery and brachial plexus is a rarity, but has enormous impact on therapy, rehabilitation and prognosis. Diagnosis of axillary artery injury may be delayed due to its varied clinical presentation and lead to prolonged ischemia, distal necrosis and even loss of limb. Thorough clinical examination, high suspicion and identification of known predictors can be helpful in early diagnosis of this rare injury. PATIENTS/MATERIAL AND METHODS: We report a case of an intoxicated 76-year-old male who sustained a dislocated proximal humerus fracture, resulting in concomitant brachial plexopathy and axillary artery dissection with secondary thrombosis after a low-energy fall from standing height. Due to mistriage as a neurological emergency the somnolent patient presented under delayed circumstances at our traumatological emergency department, demonstrating pain, paleness, paralysis, paresthesia and non-palpable wrist pulses. Diagnosis was made through high suspicion after clinical examination with the aid of CT angiography. Emergent open reduction and anatomic shoulder hemiarthroplasty was performed followed by axillobrachial interposition grafting using a reversed saphenous vein graft and brachial plexus exploration. RESULTS: The surgical treatments were uncomplicated. The affected limb remains viable at 6-week follow-up; however, active shoulder function is limited due to residual brachial plexopathy. CONCLUSION: Despite early diagnosis and management of this rare injury, the prognosis for functional recovery is guarded and largely dictated by the extent of neurological injury in the setting of concomitant brachial plexopathy. Brachial plexopathy is highly associated with axillary artery injury and its impact often underestimated in comparison due to its non-limb-threatening nature in the acute setting. Future studies should focus on the long-term prognosis for functional recovery in patients with this rare injury pattern.

Graft remodeling during growth following anterior cruciate ligament reconstruction in skeletally immature sheep.

INTRODUCTION: Ruptures of the anterior cruciate ligament are being diagnosed with increasing frequency in skeletally immature individuals. It was our aim to investigate the graft remodelling process following an autologous, transphyseal reconstruction of the anterior cruciate ligament (ACL) in skeletally immature sheep. We hypothesized that the ligamentisation process in immature sheep is quicker and more complete when compared to adult sheep. MATERIALS AND METHODS: Skeletally immature sheep with an age of 4 months underwent a fully transphyseal ACL reconstruction using an autologous tendon. The animals were subsequently sacrificed at 3, 6, 12 and 24 weeks following surgery. Each group was characterised histomorphometrically, by immunostaining (VEGF, SMA), by transmission electron microscopy (TEM) and biomechanically (UFS Roboter). RESULTS: The histomorphometric analysis and presence of VEGF and SMA positive cells demonstrated a rapid return to a ligament like structure. The biomechanical analysis revealed an anteroposterior translation that was still increased even 6 months following surgery. CONCLUSION: As in adult sheep models, the remodeling of a soft tissue graft used for ACL reconstruction results in a biomechanically inferior substitute. However, the immature tissue seems to remodel faster and more complete when compared to adults.

Histologic and biomechanical analysis of anterior cruciate ligament graft to bone healing in skeletally immature sheep.

PURPOSE: It was our aim to establish an animal model and to investigate the tendon graft-to-bone and physis healing process in skeletally immature sheep after reconstruction of the anterior cruciate ligament (ACL). METHODS: Thirty-two immature sheep aged 4 months underwent a fully transphyseal ACL reconstruction by use of a soft-tissue graft. The animals were subsequently killed after 3, 6, 12, and 24 weeks and analyzed histologically and biomechanically. RESULTS: There was a transient hypertrophy of the physis tissue at the passing site of the graft. Anchoring Sharpey-like fibers evolved as early as 3 weeks after surgery. A strong expression of collagen III messenger ribonucleic acid within the first 6 weeks preceded this anchoring process. The maximum load to failure of the tendon graft in the reconstructed knees initially decreased to 37.8 +/- 17.8 N after 3 weeks and was restored to 522.9 +/- 113 N after 24 weeks. Tendon graft stiffness was restored to 86% when compared with the control knees. CONCLUSIONS: The early anchoring by Sharpey fibers was found at 3 weeks with continued maturation to 24 weeks. This development of anchoring fibers corresponded to that of biomechanical strength, starting with 5% of the normal knee at 3 weeks and then 15.2% at 6 weeks, 41.2% at 12 weeks, and 69% at 24 weeks. Tendon graft-to-bone and physis healing in skeletally immature sheep is further characterized by a transient hypertrophy of the physis cartilage. The physis recovers well from the trauma of drilling and placement of a soft-tissue graft. The early development of Sharpey-like fibers results in a solid integration of the graft into bone in a timely manner. CLINICAL RELEVANCE: ACL reconstruction in skeletally immature individuals is still controversial. This study describes in detail the histologic and biomechanical stages of tendon graft healing to the bone and physis. These data enrich the existing knowledge of previous studies in adult sheep and may provide a basis for further research in the controversial field of ACL reconstruction during growth.

Cyclic strain induces FosB and initiates osteogenic differentiation of mesenchymal cells.

Mechanical loading is crucial for bone remodeling and osteoblast differentiation. FosB belongs to the AP-1 family of transcription factors, a group of proteins known to regulate osteoblast differentiation and bone formation. In mice, FosB is rapidly induced by mechanical stress at the transcriptional level. The aim of this study was to determine the effect of different mechanical stretch patterns on FosB gene expression and on osteogenic differentiation of human osteoblast precursor cells. Human bone-marrow-derived mesenchymal precursor cells were grown in flexible silicone dishes and stimulated by a daily application of three rounds of 2 h of cyclic stretch of either 2% or 8% elongation at 1 Hz on 3 consecutive days using a special motor-driven apparatus. By real-time PCR, we quantified FosB mRNA and the expression of genes involved in osteoblast differentiation such as Runx2 and collagen 1 to determine the osteogenic effect of mechanical stretch. Stretching induced FosB transcription and the expression of osteoblast markers in partly committed human mesenchymal precursor cells in a stretch- and time-dependent manner. We conclude that cyclic stretch-induced FosB expression and the upregulation of osteoblast genes plays a role in osteogenic differentiation of human mesenchymal precursor cells.

A system for engineering an osteochondral construct in the shape of an articular surface: preliminary results.

A tissue-engineered articular condyle could provide a new alternative approach to joint replacement. This study describes progress made towards engineering an articular condyle in vitro using human bone marrow stromal cells (hBMSCs) in a biphasic matrix. hBMSCs were transferred to a rat collagen-I hydrogel which was then pressed onto a bovine cancellous bone matrix. The gel/cell suspensions, each at a density of approximately 5 x 10(5)cells/ml containing fourth passage cells pressed into an adult human tibial condyle form using CT scan based moulds. The osteochondral constructs fabricated in vitro were stimulated in a bioreactor using cyclic compression and continuous perfusion. Penetration and cell distribution were demonstrated as homogeneous and cells were found to be viable after gel compression. The filamentous structure of the collagen fibres was more dense and homogeneous using compression. Mechanical tests showed a significant enhancement of primary matrix stability after initial compression. Stiffness was not observed to increase significantly over 7 days under loading in a bioreactor. The successful integration of mechanical stimulation in the tissue engineering process leads to an improvement in the structural and biomechanical properties of these tissues and offers new possibilities in the management of joint injuries and degenerative diseases. Remarkably, the stiffness was enhanced in our setting after initial compression of the construct in the glass cylinder without observing a negative influence on cell viability. Further studies need to clarify the influence of compression and various mechanical and hydrostatic stress patterns over different periods of time.

Eccentric training decreases paratendon capillary blood flow and preserves paratendon oxygen saturation in chronic achilles tendinopathy.

STUDY DESIGN: A controlled, randomized, prospective study, OBJECTIVE: To assess the changes in paratendon microcirculation after 12 weeks of daily painful eccentric training in individuals with chronic Achilles tendinopathy. BACKGROUND: Changes in tendon and paratendon microcirculation are evident in insertional and midportion Achilles tendinopathy. Whether the paratendon is involved in eccentric training response is not known. METHODS: Twenty patients with chronic Achilles tendinopathy were recruited for a prospective, controlled trial using eccentric exercise. A laser Doppler system assessed capillary blood flow (flow), tissue oxygen saturation (SO2), and postcapillary venous filling pressure (rHb) at 8 paratendon locations at depths of 2 and 8 mm. RESULTS: Pain in the eccentric-training group was reduced by 48% (from a mean of 4.1 +/- 2.9 to 2.1 +/- 2.2, P<.05). Deep paratendon blood flow decreased at the midportion paratendon location (P<.05). Superficial blood flow at the medial distal midportion position (by 31%, P = .008) and the lateral proximal midportion location (by 45%, P = .016) were significantly decreased postintervention, No significant change of superficial or deep paratendon oxygenation was found after intervention as compared to baseline. Deep paratendon postcapillary venous filling pressures were significantly reduced following eccentric training (P<.05). CONCLUSION: An eccentric-training program performed daily over 12 weeks reduced the increased paratendinous capillary blood flow in Achilles tendinopathy by as much as 45% and decreased pain level based on a visual analog scale. Local paratendon oxygenation was preserved while paratendinous postcapillary venous filling pressures were reduced after 12 weeks of eccentric training, which appears to be beneficial from the perspective of microcirculation.

Case Report of a Traumatic Atlantoaxial Rotatory Subluxation with Bilateral Locked Cervical Facets: Management, Treatment, and Outcome.

The aim was to report a rare case of isolated traumatic atlantoaxial rotatory subluxation without ligamentous injury. Management consisted of analgesia, sedation, and application of a halo skull traction device. After removing halo skull traction, full reduction and recovery were achieved without instability.