Arthroscopic rod technique compared to stress ultrasound in the dynamic evaluation of lateral ligament instabilities of the elbow.

INTRODUCTION: The purpose was to compare the arthroscopic rod technique to stress ultrasound in the dynamic assessment of lateral elbow instabilities. MATERIALS AND METHODS: Fifteen elbows of eight specimen with a mean age of 66.4 ± 13.3 years were assessed in a prone position following a defined dissection setup. After evaluation of the native status, an arthroscopic dissection of the radial collateral ligament (RCL) or lateral ulnar collateral ligament (LUCL), and finally of entire capsuloligamentous structures was performed. Three raters examined each state (native, RCL or LUCL lesion, complete lesion) with the arthroscopic rod technique in 90° flexion and with stress ultrasound in 30 and 90° flexion. The intra-class correlation coefficient (ICC) was calculated to assess the interrater reliability as well as test-retest reliability for each testing modality (arthroscopy and ultrasound). RESULTS: The arthroscopic rod technique showed a superior interrater and test-retest reliability of 0.953 and 0.959 (P < 0.001), respectively, when compared to stress ultrasound with an ICC of 0.4 and 0.611 (P < 0.001). A joint space opening during arthroscopy of > 6 mm humero-ulnar or > 7 mm humero-radial was indicative for a lateral collateral ligament lesion. However, a differentiation between an isolated RCL or LUCL tear was not possible. A lateral joint opening of ≥ 9 mm was only observed in complete tears of the lateral capsuloligamentous complex. CONCLUSIONS: The arthroscopic rod technique showed a superior interrater and test-retest reliability when compared to stress ultrasound. Arthroscopic assessment for radial elbow instability was found to be reliable and reproducible. A joint gapping ≥ 9 mm in the arthroscopic evaluation is a sign for a complete insufficiency of the radial capsuloligamentous complex. However, it is not possible to precisely distinguish between a lesion of the RCL or LUCL by arthroscopy. On the basis of our results, dynamic ultrasound testing may be inappropriate to objectify lateral elbow instability.

LUCL reconstruction of the elbow: clinical midterm results based on the underlying pathogenesis.

PURPOSE: Traumatic and atraumatic insufficiency of the lateral ulnar collateral ligament (LUCL) can cause posterolateral rotatory instability (PLRI) of the elbow. The influence of the underlying pathogenesis on functional outcomes remains unknown so far. The objective of this study was to determine the impact of the initial pathogenesis of PLRI on clinical outcomes after LUCL reconstruction using an ipsilateral triceps tendon autograft. METHODS: Thirty-six patients were reviewed in this retrospective study. Depending on the pathogenesis patients were assigned to either group EPI (atraumatic, secondary LUCL insufficiency due to chronic epicondylopathia) or group TRAUMA (traumatic LUCL lesion). Range-of-motion (ROM) and posterolateral joint stability were evaluated preoperatively and at follow-up survey. For clinical assessment, the Mayo elbow performance (MEPS) score was used. Patient-reported outcomes (PROs) consisting of visual analogue scale (VAS) for pain, disability of arm, shoulder and hand (DASH) score, patient-rated elbow evaluation (PREE) score and subjective elbow evaluation (SEV) as well as complications were analyzed. RESULTS: Thirty-one patients (group EPI, n = 17; group TRAUMA, n = 14), 13 men and 18 women with a mean age of 42.9 ± 11.0 were available for follow-up evaluation (57.7 ± 17.5 months). In 93.5%, posterolateral elbow stability was restored (n = 2 with re-instability, both group TRAUMA). No differences were seen between groups in relation to ROM. Even though group EPI (98.9 ± 3.7 points) showed better results than group TRAUMA (91.1 ± 12.6 points) (p = 0.034) according to MEPS, no differences were found for evaluated PROs (group A: VAS 1 ± 1.8, PREE 9.3 ± 15.7, DASH 7.7 ± 11.9, SEV 92.9 ± 8.3 vs. group B: VAS 1.9 ± 3.2, PREE 22.4 ± 26.1, DASH 16.0 ± 19.4, SEV 87.9 ± 15.4. 12.9% of patients required revision surgery. CONCLUSION: LUCL reconstruction using a triceps tendon autograft for the treatment of PLRI provides good to excellent clinical outcomes regardless of the underlying pathogenesis (traumatic vs. atraumatic). However, in the present case series, posterolateral re-instability tends to be higher for traumatic PLRI and patient-reported outcomes showed inferior results. LEVEL OF EVIDENCE: Therapeutic study, LEVEL III.

The value of elbow arthroscopy in diagnosing and treatment of radial head fractures.

BACKGROUND: Surgical treatment of radial head fractures is increasingly performed arthroscopically. These fractures often feature concomitant injuries to the elbow joint, which may be under-diagnosed in the radiological examinations. Little is known about the diagnostic value of arthroscopy, the treatment options that arise from arthroscopically assisted fracture fixation and clinical results. We hypothesized that arthroscopy can detect additional concomitant injuries and simultaneously expands the therapeutic options. Therefore aim of this study was to compare arthroscopic and radiologic findings, to assess the distinct arthroscopic procedures and to follow up on the clinical outcomes. METHODS: Twenty patients with radial head fractures were retrospectively included in two study centers. All patients underwent elbow arthroscopy due to at least one of the following suspected concomitant injuries: osteochondral lesions of the humeral capitellum, injuries of the collateral ligaments or loose joint bodies. Preoperative radiological findings were compared to arthroscopic findings. Afterwards, arthroscopic treatment options and clinical outcomes were assessed. RESULTS: Arthroscopic findings led to revision of the classified fracture type in 70% (p = 0.001) when compared to preoperative conventional radiographs (CR) and in 9% (p = 0.598) when compared to computed tomography (CT) or magnetic resonance imaging (MRI). Diagnosis of loose bodies was missed in 60% (p < 0.001) of the CR and in 18% (p = 0.269) of the CT/MRI scans. Osteochondral lesions were not identified in 94% (p < 0.001) of the CR and in 27% (p = 0.17) of the CT/MRI scans. Percutaneous screw fixation was performed in 65% and partial radial head resection in 10%. Arthroscopy revealed elbow instability in 35%, leading to lateral collateral ligament reconstruction. After a mean follow up of 41.4 ± 3.4 months functional outcome was excellent in all cases (DASH-Score 0.6 ± 0.8; MEPI-Score 98.5 ± 2.4; OES-Score 47.3 ± 1.1). CONCLUSIONS: Elbow arthroscopy has a significant diagnostic value in radial head fractures when compared to standard radiological imaging. Although statistically not significant, arthroscopy also revealed concomitant injuries in patients that presented with an uneventful MRI/CT. Furthermore, all intraarticular findings could be treated arthroscopically allowing for excellent functional outcomes. TRIAL REGISTRATION: Institutional Review Board University of Munich (LMU), Trial Number 507-14.

Proximal radius fracture morphology following axial force impact: a biomechanical evaluation of fracture patterns.

BACKGROUND: The most common location for articular fractures of the radial head is often reported to be the anterior lateral aspect of the radial head with the arm in neutral position. However, these findings mainly base on clinical observations rather than precise biomechanical measurements. The purpose of this study was to evaluate the formation of proximal radius fractures, the association between axial forces and fracture morphology, energy to failure and bone stiffness in a biomechanical in-vitro setup. METHODS: 18 fresh-frozen cadaveric radii performed axial load compression with 10 mm/min loading until bone failure. Energy to failure and bone stiffness were recorded. Proximal radial head fracture morphology and affection of the anterolateral quadrant were optically analyzed. RESULTS: All radii survived a compression load of 500 N. The mean compressive forces that lead to failure were 2,56 kN (range 1,30 - 7,32). The mean stiffness was 3,5 kN/mm (range 2,0 - 4,9). 11 radial neck fractures and 7 radial neck and radial head multifragment fractures were documented. The anterolateral quadrant was involved in 78% of tested radii. CONCLUSION: The anterolateral quadrant of the radial head (in neutral position of the forearm) is confirmed to be the most common location for articular radial head fractures in a biomechanical setting. In case of a fall on the outstretched arm radial neck fractures should be securely ruled out due to prior occurrence to radial neck and head fractures.

A combination of an anteromedial, anterolateral and midlateral portals is sufficient for 360° exposure of the radial head for arthroscopic fracture fixation.

PURPOSE: Arthroscopic fixation of radial head fractures is an alternative to open reduction and internal fixation; the latter, however, presents the advantage of minimal soft-tissue damage. The exposure of the radial head for adequate screw placement can be technically challenging. The aim of this study was to evaluate the inter-observer agreement on the effective contact arc in the axial plane of the radial head of three different elbow arthroscopy portals. METHODS: A fresh-frozen cadaver specimen was obtained and prepared in an arthroscopic setting. Standard anterolateral (AL), anteromedial (AM), and midlateral (ML) portals were established and a circular reference system was marked on the radial head. Ten orthopaedic surgeons were then asked to move the forearm from maximal supination to maximal pronation and indicate with a Kirschner wire from each portal the extension in which they would feel confident in placing a cannulated screw passing through the centre of the articular plane of the radial head (axial contact arc). The Shapiro-Wilk normality test was used to evaluate the normal distribution of the sample. A coefficient of variation (CoV) was calculated to determine agreement among observers. RESULTS: The average arc of axial contact arc that could be contacted from the AM portal measured 150 ± 14.1°, or 41.7% of the radial head circumference; the one from the AL portal measured 257 ± 29.5°, or 71.4% of the radial head circumference; that from the ML portal measured 212.5 ± 32.6°, or 59.0% of the radial head circumference. Considering all three portals, the whole radial head circumference could be contacted. The AM portal showed the smallest CoV (9.4%) as compared to the AL (11.5%), and the ML (15.3%) portals. CONCLUSIONS: With an appropriate use of the standard AL, AM, and ML portals, the whole radial head circumference can be effectively exposed for adequate fixation of radial head fractures. The contact arc of the AM portal presents the smallest variability among different observers and the AL portal shows a superiority in axial contact arc. This information is important for pre-operative planning, and helps to define the limits of arthroscopic radial head fracture fixation.

Intramedullary Cortical Button Repair for Distal Biceps Tendon Rupture: A Single-Center Experience.

PURPOSE: The aim of this retrospective study was to evaluate the clinical outcome and complication rate of intramedullary cortical button repair for distal biceps tendon rupture (partial and complete tears). METHODS: Between 2010 and 2014, a total of 28 patients with an acute distal biceps tendon rupture underwent intramedullary cortical button repair. Twenty-four patients (mean age, 49 years) with a mean follow-up of 28 months were included in the study. Twenty patients were examined clinically and by maximum isometric strength testing in flexion (at 90°) and supination of both arms. Twenty-four patients completed functional scores including the Mayo Elbow Performance Score (MEPS), the Andrews-Carson-Score (ACS) and the shortened Disabilities of the Arm, Shoulder, and Hand (QuickDASH) questionnaire. Furthermore, follow-up radiographs of 24 patients were analyzed. RESULTS: Compared with the contralateral elbow, the active range of motion (ROM) was the same. The mean strength for flexion was 100.8% ± 14% and for supination 93.1% ± 22% compared with the uninjured side. The mean MEPS for all patients was 95.6 ± 8.2, the mean ACS 194.2 ± 9.4 and the QuickDASH 3.8 ± 7.6. Heterotopic ossification (HO) was seen on radiographs in 46% of patients, but was symptomatic in only 1 patient. One patient suffered a tendon rerupture, and 1 asymptomatic button migration was seen in the follow-up. CONCLUSIONS: Intramedullary cortical button repair provides good results with respect to strength, ROM, and functional outcomes. Because the posterior cortex is not violated, the risk of iatrogenic posterior interosseous nerve injury is minimized. However, the patient should be warned of a high prevalence of postoperative HO. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

The influence of radio frequency ablation on intra-articular fluid temperature in the ankle joint - a cadaver study.

BACKGROUND: Radio frequency ablation devices have found a widespread application in arthroscopic surgery. However, recent publications report about elevated temperatures, which may cause damage to the capsular tissue and especially to chondrocytes. The purpose of this study was the investigation of the maximum temperatures that occur in the ankle joint with the use of a commercially available radio frequency ablation device. METHODS: Six formalin-fixed cadaver ankle specimens were used for this study. The radio frequency device was applied for 120 s to remove tissue. Intra-articular temperatures were logged every second for 120 s at a distance of 3, 5 and 10 mm from the tip of the radio frequency device. The irrigation fluid flow was controlled by setting the inflow pressure to 10 mmHg, 25 mmHg, 50 mmHg and 100 mmHg, respectively. The controller unit voltage setting was set to 1, 5 and 9. RESULTS: Maximum temperatures exceeding 50 °C/122 °F were observed for all combinations of parameters, except for those with a pressure of 100 mmHg pressure. The main critical variable is the pressure setting, which is highly significant. The controller unit voltage setting showed no effect on the temperature measurements. The highest temperature was 102.7 °C/215.6 °F measured for an irrigation flow of 10 mmHg. The shortest time span to exceed 50 °C/122 °F was 3 s. CONCLUSION: In order to avoid temperatures exceeding 50 °C/122 °F in the use of radio frequency devices in arthroscopic surgeries of the ankle joint, it is recommended to use a high irrigation flow by setting the pressure difference across the ankle joint as high as feasible. Even short intervals of a low irrigation flow may lead to critical temperatures above 50 °C/122 °F. LEVEL OF EVIDENCE: Level II, diagnostic study.

Reattachment of the flexor and extensor tendons at the epicondyle in elbow instability: a biomechanical comparison of techniques.

BACKGROUND: Elbow dislocation represents a common injury, especially in the younger population. If treated surgically, the reattached tendons require a high amount of primary stability to allow for an early rehabilitation to avoid postoperative stiffness. The purpose of this study was to assess the biomechanical properties of a single and a double row technique for reattachment of the common extensor and common flexor muscles origin. We hypothesized that the double row technique would provide greater stability in terms of pullout forces than the single row technique. METHODS: Twelve cadaveric specimens were randomized into two groups of fixation methods for the common extensor tendon or the common flexor tendon at the elbow (1): a single row technique using two knotted 3.0 mm suture anchors, and (2) a double row technique using an additional knotless 3.5 mm anchor. The repairs were cyclically loaded over 500 cycles at 1 Hz from 10 N to a maximum of 100 N (extensors) or 150 N (flexors), and then pulled to failure. Stiffness and maximum load at failure and mode of failure were recorded and calculated. RESULTS: No significant differences in stiffness were observed between the two techniques for both the extensor and flexor reattachment (P = 0.701 and P = 0.306, respectively). The mean maximum load at failure indicated that the double row construct was significantly stronger than the single row construct. This was found to be true for both the extensor and flexor reattachment (213.6; SD 78.7 N versus 384.1; SD 105.6 N, P = 0.010 and 203.7; SD 65.8 N versus 318.0; SD 64.6 N, P = 0.013, respectively). CONCLUSIONS: The double row technique provides significant greater stability to the reattached common flexor or extensor origin to the medial or lateral epicondyle. Thus, it should be considered in the development of improved repair techniques for stabilizers of the elbow. STUDY DESIGN: Controlled laboratory study.

Arthroscopic arthrolysis provides good clinical outcome in post-traumatic and degenerative elbow stiffness.

PURPOSE AND HYPOTHESIS: The purpose of this retrospective study was to report on the functional outcome after arthroscopic arthrolysis in patients with post-traumatic or degenerative elbow stiffness. It was hypothesized that this operative procedure leads to improved range of motion (ROM) and improved functional outcome in both groups. METHODS: Patients who underwent arthroscopic arthrolysis of the elbow between 2010 and 2015 were included in this study. Forty-two patients with an average age of 41.0 ± 13.5 years were available for evaluation. The mean follow-up was 28.3 ± 14.9 months. With regard to aetiology of elbow contractures, patients were divided into post-traumatic (group A) and degenerative (group B) cohort. General patients' data, previous surgical treatment and ROM were recorded. At follow-up evaluation, the clinical outcome was assessed by the ROM, visual analogue scale (VAS) for pain assessment and the Elbow Self-Assessment Score (ESAS). RESULTS: The mean arc of motion of group A (n = 20) increased from preoperatively 74.3° to 120.5° postoperatively (p < 0.001); group B (n = 22) showed an improvement of 104.6° preoperatively to 123.4° after surgery (p = 0.002). Mean improvement was 46.3° ± 27.5° in group A and 16.4° ± 19.4° in group B. Mean post-operative VAS was 0.9 ± 1.5 in group A and 1.3 ± 2.2 in group B. 92.9% of patients achieved a functional arc of elbow motion >100°. The ESAS indicated good to excellent clinical outcome showing 88.8 ± 10.0 points in group A and 84.1 ± 21.4 points in group B. Thirty-six patients (85.7%) returned to their previous work level after surgery. CONCLUSIONS: Arthroscopic arthrolysis is an effective treatment option for patients with restriction in elbow motion reasoned by post-traumatic or degenerative changes. Both groups showed a significant improvement of ROM and comparable outcome scores. LEVEL OF EVIDENCE: Therapeutic study, Level IV.

The Elbow Self-Assessment Score (ESAS): development and validation of a new patient-reported outcome measurement tool for elbow disorders.

PURPOSE: To develop and validate an elbow self-assessment score considering subjective as well as objective parameters. METHODS: Each scale of the American Shoulder and Elbow Surgeons-Elbow Score, the Broberg and Morrey rating system (BMS), the Patient-Rated Elbow Evaluation (PREE) Questionnaire, the Mayo Elbow Performance Score (MEPS), the Oxford Elbow Score (OES) and the Quick Disabilities of the Arm, Shoulder and Hand (Quick-DASH) was analysed, and after matching of the general topics, the dedicated items underwent a fusion to the final ESAS's item and a score containing 22 items was created. In a prospective clinical study, validity, reliability and responsiveness in physically active patients with traumatic as well as degenerative elbow disorders were evaluated. RESULTS: Validation study included 103 patients (48 women, 55 men; mean age 43 years). A high test-retest reliability was found with intraclass correlation coefficients of at least 0.71. Construct validity and responsiveness were confirmed by correlation coefficients of -0.80 to -0.84 and 0.72-0.84 (p <0.05). Correlation coefficients of the ESAS and well-established elbow rating systems BMS, PREE, MEPS, OES and Quick-DASH were between 0.70 and 0.90 (p < 0.05). CONCLUSIONS: With this novel Elbow Self-Assessment Score (ESAS), a valid and reliable instrument for a qualitative self-assessment of subjective and objective parameters (e.g. range of motion) of the elbow joint is demonstrated. Quantitative measurement of elbow function may not longer be limited to specific elbow disorders or patient groups. The ESAS seems to allow for a broad application in clinical research studying elbow patients and may facilitate the comparison of treatment results in elbow disorders. The treatment efficacy can be easily evaluated, and treatment concepts could be reviewed and revised. LEVEL OF EVIDENCE: Diagnostic study, Level III.

Novel technique for sternoclavicular joint reconstruction using a gracilis tendon autograft.

UNLABELLED: Surgical treatment of sternoclavicular joint instability can be challenging and carries the inherent risk of damaging vital structures if the posterior capsule is violated during surgery. In the current manuscript, a novel and easy technique for open reduction and tendon graft stabilization of the unstable sternoclavicular joint is presented. Analogous to other techniques, the graft is passed through drill holes in a figure-of-eight configuration. However, for this technique, the drill holes are placed in oblique direction from the anterior cortex towards the articular surface of the sternum, respectively the medial clavicle. By doing so, graft reconstruction is achieved without any need for retrosternal dissection and mobilization of the posterior capsule, thus minimizing the risk of severe intraoperative complications. LEVEL OF EVIDENCE: V.

Avulsion of the anterior medial meniscus root: case report and surgical technique.

Injuries of the meniscus roots have become increasingly recognised as a serious pathology of the knee joint. However, the current available literature focuses primarily on posterior meniscus root tears. In this article, a case with an isolated avulsion of the anterior medial meniscus root is presented, and a new arthroscopic technique to treat this type of injury is described. The anterior horn of the medial meniscus was sutured with a double-looped nonabsorbable suture and reattached to the tibial plateau using a knotless suture anchor. This technique may also be useful to treat avulsion injuries of the anterolateral or posteromedial meniscus root, and symptomatic subluxation of the medial meniscus in case of a variant insertion anatomy with an absent attachment of the anterior horn of the medial meniscus to the tibial plateau. Level of evidence V.

Double intramedullary cortical button versus suture anchors for distal biceps tendon repair: a biomechanical comparison.

PURPOSE: The aim of this biomechanical in vitro study was to compare the novel technique of double intramedullary cortical button (DICB) fixation with the well-established method of suture anchor (SA) fixation for distal biceps tendon repair. METHODS: A matched-pair analysis (24 human cadaveric radii) was performed with respect to cyclic loadings and failure strengths. Twelve specimens per group were cyclically loaded for 1,000 cycles at 1.5 Hz from 5 to 50 N and from 5 to 100 N, respectively. The tendon-bone displacement was optically analysed using the Image J Software (National Institute of Health). Afterwards, all specimens were pulled to failure. Maximum load to failure and mode of failure were recorded. RESULTS: All DICB constructs passed the cyclic loading test, whereas 4 of the 12 specimens within the SA group failed by anchor pull-out. Cyclic loading showed a mean tendon-bone displacement of 0.6 ± 1.4 mm for the DICB group and 1.4 ± 1.4 mm for the SA group (n.s.) after 1,000 cycles with 50 N, and a mean displacement of 2.1 ± 2.4 mm for the DICB group and 3.5 ± 3.7 mm for the SA group (n.s.) after 1,000 cycles with 100 N. Load to failure testing showed a mean failure load of 312 ± 76 N and a stiffness of 67.1 ± 11.7 N/mm for the DICB technique. The mean load to failure for the SA repair was 200 ± 120 N (n.s.) and the stiffness was 55.9 ± 21.3 N/mm (n.s.). CONCLUSIONS: The novel technique of DICB fixation showed small tendon-bone displacement during cyclic testing and reliable fixation strength to the bone in load to failure. Moreover, all DICB constructs passed cyclic loadings without failure. Based on the current findings, a more aggressive postoperative rehabilitation may be allowed for the DICB repair in clinical use.

Biomechanical comparison of intramedullary cortical button fixation and interference screw technique for subpectoral biceps tenodesis.

PURPOSE: The purpose of this study was to biomechanically evaluate a new technique of intramedullary cortical button fixation for subpectoral biceps tenodesis and to compare it with the interference screw technique. METHODS: We compared intramedullary unicortical button fixation (BicepsButton; Arthrex, Naples, FL) with interference screw fixation (Bio-Tenodesis screw; Arthrex) for subpectoral biceps tenodesis using 10 pairs of human cadaveric shoulders and ovine superficial digital flexor tendons. After computed tomography analysis, the specimens were mounted in a testing machine. Cyclic loading was performed (preload, 5 N; 5 to 70 N at 1.5 Hz for 500 cycles), recording the displacement of the tendon. Load to failure and stiffness were subsequently evaluated with a load-to-failure test (1 mm/s). RESULTS: Cyclic loading showed a displacement of 11.3 ± 2.8 mm for intramedullary cortical button fixation and 9 ± 1.7 mm for interference screw fixation (P = .112). All specimens within the cortical button group passed the cyclic loading test, whereas 3 of 10 specimens within the interference screw group failed by tendon slippage at the screw-tendon-bone interface after a mean of 252 cycles (P = .221). Load-to-failure testing showed a mean load to failure of 218.8 ± 40 N and stiffness of 27.2 ± 7.2 N/mm for the intramedullary cortical button technique. For the interference screw, the mean load to failure was 212.1 ± 28.3 N (P = .625) and stiffness was 40.4 ± 13 N/mm (P = .056). CONCLUSIONS: We could not find any major differences in load to failure when comparing the tested techniques for subpectoral biceps tenodesis. Intramedullary cortical button fixation showed no failure during cyclic testing. However, we found a 30% failure rate (3 of 10) for the interference screw fixation. CLINICAL RELEVANCE: Intramedullary cortical button fixation provides an alternative technique for subpectoral biceps tenodesis with comparable and, during cyclic loading, even superior biomechanical properties to interference screw fixation.

Acromioclavicular and coracoclavicular PDS augmentation for complete AC joint dislocation showed insufficient properties in a cadaver model.

PURPOSE: Optimal surgical treatment of high-grade acromioclavicular joint dislocations is still controversially discussed. The purpose of the present controlled laboratory study was to evaluate whether a polydioxansulfate (PDS(®)) cord augmentation with separate reconstruction of the coracoclavicular (CC) ligaments and the acromioclavicular (AC) complex provides sufficient vertical stability in a biomechanical cadaver model. METHODS: Twenty-four shoulders of fresh-frozen cadaveric specimen were tested. Cyclic loading and load to failure protocol was performed in vertical direction on 12 native AC joints and repeated after reconstruction. The reconstruction of the coracoclavicular ligament was performed using two CC PDS cerclages and an additional AC PDS cerclage. RESULTS: In static load testing for vertical force, the native AC joint complex measured 590.1 N (±95.8 N), elongation 13.4 mm (±2.1 mm) and stiffness 48.7 N/mm (±12.0 N/mm). The mean maximum load to failure in the reconstructed joints was 569.9 N (±97.9 N), elongation 18.8 mm (±4.7 mm) and stiffness 37.9 N/mm (±8.0 N/mm). During dynamic testing of the reconstructed AC joints, all specimens reached the critical elongation of 12.0 mm, defined as clinical failure between 200 and 300 N. The mean amount of repetitions at clinical failure was 305. A plastic deformation of the reconstructed specimens throughout cyclic loading could not be detected. CONCLUSION: The AC joint reconstruction with acromioclavicular and coracoclavicular PDS cord cerclages did not provide the aspired vertical stability in a cadaver model. LEVEL OF EVIDENCE: Basic Science Study.

[Ligamentous elbow injuries-When is surgical treatment still indicated?] / Ligamentäre Ellenbogenverletzung ­ Wann ist die operative Therapie noch indiziert?

The elbow joint is a hinge-type synovial joint and is the second most frequently dislocated joint in adults and the most frequently dislocated joint in children. To find the right treatment options a precise understanding of the injury pattern, anatomy, biomechanics and pathology (simple vs. complex dislocation) is essential for a good reconstruction of the function and to prevent chronic instability and pain. The differentiation between acute and chronic instability gives another variation in the treatment plan. According to the latest literature there are clear indications for surgery of a complex elbow dislocation, whereas for simple dislocations conservative treatment is preferentially recommended; however, when is the surgical treatment of a ligamentous elbow dislocation (still) indicated?

[Return to throwing sports after upper extremity injury and overuse : A criteria-based approach using an ulnar collateral ligament injury as an example]. / Zurück zum Wurfsport nach Verletzung und Überlastung an der oberen Extremität : Ein kriterienbasierter Ansatz am Beispiel einer Verletzung des Ligamentum collaterale ulnare.

BACKGROUND: Uniform procedures for rehabilitation and follow-up treatment after injuries and surgeries at the upper extremity do not exist. Accordingly, only a few approaches for the follow-up treatment of instabilities of the elbow joint have been described. OBJECTIVES: The authors show how rehabilitation before sport-specific training after rupture of the ulnar collateral ligament in a female handball player was objectivized and controlled using the results of functional tests. MATERIALS AND METHODS: The follow-up treatment of a semi-professional female handball player (aged 20) after rupture of the ulnar collateral ligament was objectivized and controlled using the return to activity algorithm. In addition to the comparisons with the values of the unaffected side, comparative results of 14 uninjured female handball players were used for guidance. RESULTS/CONCLUSIONS: The patient was able to participate fully in sport-specific training after 15 weeks and participate in her first competitive match after 20 weeks. On the affected side, she achieved a distance of 118% of her upper limb length on the medial reach of the upper quarter Y balance test and 63 valid contacts on the wall hop test. The values achieved at the end of rehabilitation were higher than the average values of the control group.

A minimally invasive stabilizing system for dorsal pelvic ring injuries.

BACKGROUND: Open reduction and stabilization of dorsal pelvic ring injuries is accompanied by a high rate of soft tissue complications. Minimally invasive techniques have the potential to decrease soft tissue trauma, but the risk of iatrogenic nerve and vessel damage through the reduced surgical exposure should be considered. We treated these injuries using a transiliac internal fixator (TIFI) in a minimally invasive technique characterized by implantation of a pedicle screw and rod system, bridging the sacroiliac joints and the sacral area. QUESTIONS/PURPOSES: We asked whether (1) we could achieve anatomic restoration with the device, (2) specific complications were associated with this minimally invasive approach (particularly enhanced intraoperative blood loss, soft tissue complications, and iatrogenic neurovascular damage), and (3) function 3 years after trauma was comparable to that of established methods. METHODS: We retrospectively reviewed 67 patients with dorsal pelvic injuries during a 7-year period. We evaluated the (1) reduction by grading the maximal displacement measured with three radiographic views, (2) the complications during the observation period, and (3) the function with a validated questionnaire (Pelvic Outcome Score) in all but five patients at least 3 years after trauma (mean, 37 months; range, 36-42 months). RESULTS: At last followup we observed a secondary fracture displacement greater than 5 mm in one patient. The intraoperative blood loss was less than 50 mL in all patients. No neurovascular lesions occurred owing to implantation. Four patients had wound infections, one had loosening of a single pedicle screw, and one had an iatrogenic screw malpositioning. Thirty-five of the 62 patients achieved Pelvic Outcome Scores of either a maximum score or 6 of 7 points. CONCLUSION: Our observations suggest TIFI is a reasonable alternative to other established fixation devices for injuries of the dorsal pelvic ring with minor risks of major blood loss or iatrogenic neurovascular damage. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Is the rotation of the femoral head a potential initiation for cutting out? A theoretical and experimental approach.

BACKGROUND: Since cut-out still remains one of the major clinical challenges in the field of osteoporotic proximal femur fractures, remarkable developments have been made in improving treatment concepts. However, the mechanics of these complications have not been fully understood.We hypothesize using the experimental data and a theoretical model that a previous rotation of the femoral head due to de-central implant positioning can initiate a cut-out. METHODS: In this investigation we analysed our experimental data using two common screws (DHS/Gamma 3) and helical blades (PFN A/TFN) for the fixation of femur fractures in a simple theoretical model applying typical gait pattern on de-central positioned implants. In previous tests during a forced implant rotation by a biomechanical testing machine in a human femoral head the two screws showed failure symptoms (2-6Nm) at the same magnitude as torques acting in the hip during daily activities with de-central implant positioning, while the helical blades showed a better stability (10-20Nm).To calculate the torque of the head around the implant only the force and the leverarm is needed (N [Nm] = F [N] * × [m]). The force F is a product of the mass M [kg] multiplied by the acceleration g [m/s2]. The leverarm is the distance between the center of the head of femur and the implant center on a horizontal line. RESULTS: Using 50% of 75 kg body weight a torque of 0.37Nm for the 1 mm decentralized position and 1.1Nm for the 3 mm decentralized position of the implant was calculated. At 250% BW, appropriate to a normal step, torques of 1.8Nm (1 mm) and 5.5Nm (3 mm) have been calculated.Comparing of the experimental and theoretical results shows that both screws fail in the same magnitude as torques occur in a more than 3 mm de-central positioned implant. CONCLUSION: We conclude the center-center position in the head of femur of any kind of lag screw or blade is to be achieved to minimize rotation of the femoral head and to prevent further mechanical complications.

The double intramedullary cortical button fixation for distal biceps tendon repair.

PURPOSE: This study was designed to present the novel technique of intramedullary cortical button fixation for distal biceps tendon repair via a single-limited anterior portal. METHODS: To reattach the ruptured biceps tendon at the radial tuberosity, two Bicepsbutton(™) (Arthrex, Naples, FL, USA) were intramedullary positioned to the anterior cortex. The surgical procedure is described in detail. This technique has been performed in a first series of 3 patients with acute distal biceps tendon ruptures. RESULTS: All patients were very satisfied after surgery and would undergo the same surgical procedure again. All patients regained full range of elbow motion with comparable strength of forearm supination and elbow flexion measured against the uninjured arm at 6 months of follow-up. No neurovascular complications have been occured. CONCLUSION: Double intramedullary cortical button repair has shown to be a safe and reliable fixation method for distal biceps tendon rupture in a small series of patients. Preliminary results are encouraging.