Analysis and 3D correction of glenoid dysplasia with metal hemi-wedge base plate augment: short-term radiographic outcomes.

BACKGROUND: Glenoid defects can be addressed traditionally by asymmetric reaming or by bone-preserving correction to a more lateral joint line by bone or metal augmented baseplates in reverse shoulder arthroplasties. While there is more evidence in literature regarding the outcome and complications of Bony Increased Offset Reversed Shoulder Arthroplasty (BIO-RSA), there is minimal reported experience with the outcome after metal glenoid augments. The aim of this study was to determine whether a metal augment can correct the glenoid deformity in an anatomic manner. METHODS: Glenoid morphology and deformity were determined in 50 patients with Walch type B1, B2, D and Favard type E0-E3 glenoid defects using preoperative radiographic and computed tomography (CT) analysis. All patients received a preoperative planning CT with 3D planning, and measurements of glenoid inclination (in 3 planes proximal, middle, distal), reversed shoulder arthroplasty angle (RSA) and glenoid version were obtained. All patients had a pathologic inclination in the coronal or frontal planes of > 10°. Above the threshold of 10° pathological glenoid version or inclination metal hemi-augments of 10°, 20°, or 30° were used which allow an individual 360° augment positioning according to the patient glenoid deformity. RESULTS: The mean preoperative numbers of the glenoid version demonstrate that most glenoids were in retroversion and superior inclination. In total 2410° wedges, 1820° wedges and 8 30° wedges were used. In the majority of cases, the wedge was positioned posteriorly and/or cranially between 10:00 and 12:00 o'clock, which allows a correction in a 3D manner of the glenoid inclination and version. The mean RSA angle could be corrected from 22.76 ± 6.06 to 0.19° ± 2.7 (p < 0.0001). The highest retroversion of the glenoid is evidenced in the proximal section and it could be corrected from - 23.32° ± 4.56 to - 6.74° ± 7.75 (p < 0.0001) and in the middle section from - 18.93° ± 3.35 to - 7.66° ± 5.28 (p < 0.0001). A mean sphere bone overhang distance (SBOD) of 5.70 ± 2.04 mm was found in order to avoid or minimize relevant scapular notching. CONCLUSION: By using a new 360° metal-augmented baseplate, the preoperative pathological inclination and retroversion can be corrected without medialization of the joint line. Future clinical results will show whether this bone-preserving procedure improves also the clinical outcomes as compared to asymmetric medialized reaming or wedged BIO-RSA. LEVEL OF EVIDENCE: Level IV, Case series.

Biomechanical analysis of the interval slide procedure: a fresh porcine cadaver study.

INTRODUCTION: The interval slide procedure (IS) has been introduced to improve mobility in massive, retracted rotator cuff tears. As clinical studies showed controversial results, the benefit of the IS is still widely discussed. AIM: Aim of this study was to analyze the effect of IS procedure on tendon mobility in a fresh porcine cadaver model. MATERIALS AND METHODS: In 30 fresh porcine cadaver shoulders with artificial supraspinatus defect tendon mobility was tested by measuring the load (in N) during tendon reduction to the footprint at the greater tubercle using a sensor enhanced arthroscopic grasper (t1). In intervention group (N = 15) anterior IS (t2), posterior IS (t3) and intraarticular capsule release (t4) were successively performed, each followed by tendon mobility assessment. Tendon mobility of the control group (N = 15) was measured in same time schedule without intervention. RESULTS: Mobility did not differ between groups for native tendons (CG 28.0 ± 11.2 N vs. IG 26.6 ± 11.6 N; P = 0.75). IS procedure significantly improves mobility at about 25.2% (t1 26.6 ± 11.6 N vs. t4 19.9 ± 12.3 N; P < 0.001) compared to the native tendon and 34.1% compared to CG (CG 30.2 ± 13.7 N vs. 19.9 ± 12.3 N; P = 0.026). In posthoc analyzes, anterior IS (P < 0.001) and capsule release (P = 0.005) significantly increased mobility, whereas the posterior IS did not (P = 0.778). CONCLUSION: The IS procedure results in increased supraspinatus tendon mobility in fresh porcine cadaver shoulders. However, performing the posterior IS subsequent to the anterior IS no significant improvement of mobility has been observed.

Long-term outcome and survival rate of monopolar radial head replacement.

BACKGROUND: The purposes of this study were (1) to report functional outcomes; (2) to assess complications, revisions, and survival rate; and (3) to assess differences in functional outcomes between removed and retained radial head arthroplasties (RHAs), early and delayed treatment, and type of RHA used at long-term follow-up after monopolar RHA for unreconstructible radial head fractures or their sequelae. METHODS: Seventy-eight patients (mean age, 59.2 years) who were at least 6 years postoperatively after monopolar RHA for unreconstructible RHFs or their sequelae were included. The Mayo Elbow Performance Score (MEPS); Quick Disability of the Arm, Shoulder, and Hand (QuickDASH) score; visual analog scale; postoperative satisfaction (1-6, 6 = highly unsatisfied); range of motion; complications; and revisions were assessed. Radiographic findings were reported. Kaplan-Meier survival analysis was performed. Subgroups (RHA type, early vs. delayed surgery, RHA removed vs. retained) were compared. RESULTS: At a median clinical follow-up of 9.5 years (range: 6.0-28.4 years), median MEPS was 80.0 (interquartile range [IQR]: 60.0-97.5), median QuickDASH was 22.0 (IQR: 4.6-42.6), median visual analog scale was 1 (IQR: 0-4), median postoperative satisfaction was 2 (IQR: 1-3), and median arc of extension/flexion was 110° (IQR: 80°-130°). Radiographic follow-up was available for 48 patients at a median of 7.0 years (range: 2.0-15.0 years). Heterotopic ossifications were seen in 14 (29.2%), moderate-to-severe capitellar osteopenia/abrasion in 3 (6.1%), moderate-to-severe ulnohumeral degeneration in 3 (6.1%), and periprosthetic radiolucencies in 17 (35.4%) patients. Twenty-nine patients (37.2%) had complications and 20 patients (25.6%) underwent RHA exchange or removal. Kaplan-Meier analysis with failure defined as RHA exchange or removal demonstrated survival of 75.1% (95% confidence interval: 63.7-83.3) at 18 years. The highest annual failure rate was observed in the first year in which the RHAs of 7 patients (9%) were exchanged or removed. No significant differences were detected between type of RHA in MEPS (Mathys: 82.5 [75.0-100] vs. Evolve: 80.0 [60.0-95.0]; P = .341) and QuickDASH (Mathys: 12.5 [0-34.4] vs. Evolve: 26.7 [6.9-46.2]; P = .112). Early surgery (≤3 weeks) yielded significantly superior MEPS (80.0 [70.0-100.0] vs. 52.5 [30.0-83.8]; P = .014) and QuickDASH (18.6 [1.5-32.6] vs. 46.2 [31.5-75.6]; P = .002) compared with delayed surgery (>3 weeks). Patients with retained RHAs had significantly better MEPS (80.0 [67.5-100] vs. 70.0 [32.5-82.5]; P = .016) and QuickDASH (18.1 [1.7-31.9] vs. 49.1 [22.1-73.8]; P = .007) compared with patients with removed RHAs. CONCLUSIONS: Long-term outcomes for RHA are satisfactory; however, there is a high complication and revision rate, resulting in implant survival of 75.1% at 18 years with the highest annual failure rate observed in the first postoperative year.

Injury patterns following simple elbow dislocation: radiological analysis implies existence of a pure valgus dislocation mechanism.

INTRODUCTION: The aim of the present study was to analyze the injury pattern and thus the dislocation mechanism after simple elbow dislocation using radiographs and magnetic resonance imaging (MRI) data sets. MATERIALS AND METHODS: The MRI data sets of 64 patients with a mean age of 44 years (18-77 years) were analyzed retrospectively. The inclusion criteria for the study were (1) radiograph with confirmed simple elbow dislocation, (2) low-energy trauma, (3) MRI of the affected elbow ≤ 3 weeks after trauma. The dislocation direction was determined using radiographs. The integrity of the lateral collateral ligament complex (LCLC), common extensor origin (CEO), anterior capsule (AC), medial collateral ligament (MCL), and common flexor origin (CFO) as well as the joint congruity were assessed based on MRI. RESULTS: 34 patients (53%) had a posterolateral, 26 patients (41%) a posterior, and 4 patients (6%) a posteromedial dislocation. LCLC and AC were affected in 64 out of 64 patients (100%). MCL was affected in 58 patients (91%). CEO were affected in 25 patients (39%) and the CFO in 20 patients (31%). In 11 patients (17%) the injury pattern was more pronounced medially than laterally (MCL, CFO, LCLC), with 2 of these patients exhibiting only a partial LCLC tear. All cases with joint incongruency (n = 12, 19%) showed CEO and/or CFO involvement. CONCLUSIONS: Simple elbow dislocation leads to a very heterogeneous spectrum of soft tissue injury pattern. A small proportion of patients showed medially pronounced injury patterns. These findings strongly indicate existence of a "reversed Horii circle" with an underlying valgus mechanism (medial force induction) originating and continuing from medial to anterior.

A new sequential animal model for infection-related non-unions with segmental bone defect.

BACKGROUND: The treatment of fracture-related infections (FRI) is still a challenge for orthopedic surgeons. The prevalence of FRI is particularly high in open fractures with extensive soft-tissue damage. This study aimed to develop a new two-step animal model for non-unions with segmental bone defects, which could be used to evaluate new innovative bone substitutes to improve the therapeutic options in humans with FRI and bone defects. METHODS: After randomization to infected or non-infected groups, 30 Sprague-Dawley rats underwent a transverse osteotomy of the mid-shaft femur with a 5 mm defect. Additionally, the periosteum at the fracture zone was cauterized at both sides. After intramedullary inoculation with 103 CFU Staphylococcus aureus (infected group) or PBS (non-infected group), a fracture stabilization was done by intramedullary K-wires. After 5 weeks, the bone healing process was evaluated, and revision surgery was performed in order to obtain increased bone healing. The initial K-wires were removed, and debridement of the osteotomy-gap was done followed by a more stable re-osteosynthesis with an angle-stable plate. After further 8 weeks all rats were euthanized and the bone consolidation was tested biomechanically and the callus formation quantitatively by micro-CT analysis. RESULTS: We developed and presented a new two-stage non-union animal model through a targeted S. aureus infection. After 5 weeks, all animals showed a non-union irrespective of assignment to the infected and non-infected group. Lane and Sandhu score showed a higher callus formation in the infected group. In all infected animals, the inoculated S. aureus strain was detected in the revision surgery. The second surgery did not improve bone healing, as shown by the Lane Sandhu score and in the µ-CT analysis. Similarly, biomechanical testing showed in both groups a significantly lower maximum torque as compared to the contralateral side (p < 0.0001). CONCLUSIONS: We were able to successfully develop a new two-stage non-union animal model, which reflects a genuine clinical situation of an infection-related non-union model with segmental bone defects. This model could be used to evaluate various therapeutic anti-infectious and osteoinductive strategies in FRIs.

Autologous Bone Graft Versus Silicate-Substituted Calcium Phosphate in the Treatment of Tunnel Defects in 2-Stage Revision Anterior Cruciate Ligament Reconstruction: A Prospective, Randomized Controlled Study With a Minimum Follow-up of 2 Years.

PURPOSE: To compare and evaluate knee laxity and functional outcomes between autologous bone graft and silicate-substituted calcium phosphate (Si-CaP) in the treatment of tunnel defects in 2-stage revision anterior cruciate ligament reconstruction (ACLR). METHODS: This prospective, randomized controlled trial was conducted between 2012 and 2015 with a total of 40 patients who underwent 2-stage revision ACLR. The tunnels were filled with autologous iliac crest cancellous bone graft in 20 patients (control group) and with Si-CaP in the other 20 patients (intervention group). After a minimum follow-up period of 2 years, functional outcomes were assessed by KT-1000 arthrometry (side-to-side [STS] difference), the Tegner score, the Lysholm score, and the International Knee Documentation Committee score. RESULTS: A total of 37 patients (follow-up rate, 92.5%) with an average age of 31 years were followed up for 3.4 years (range, 2.2-5.5 years). The KT-1000 measurement did not show any STS difference between the bone graft group (0.9 ± 1.5 mm) and the Si-CaP group (0.7 ± 2.0 mm) (P = .731). One patient in the intervention group (5%) had an STS difference greater than 5 mm. Both groups showed significant improvements in the Tegner score, Lysholm score, and International Knee Documentation Committee score from preoperative assessment to final follow-up (P ≤ .002), without any difference between the 2 groups (P ≥ .396). Complications requiring revision occurred in 4 control patients (22%) and in 2 patients in the intervention group (11%) (P = .660). No complications in relation to Si-CaP were observed. CONCLUSIONS: Equivalent knee laxity and clinical function outcomes were noted 3 years after surgery in both groups of patients. Si-CaP bone substitute is therefore a safe alternative to autologous bone graft for 2-stage ACLR. LEVEL OF EVIDENCE: Level I, prospective, randomized controlled clinical trial.

Functional outcome and tendon integrity of rotator cuff reconstruction after primary traumatic glenohumeral dislocation.

INTRODUCTION: Rotator cuff tears (rct) subsequent to glenohumeral dislocation are relevant concomitant injuries, can lead to impaired shoulder function and increase risk of recurrent dislocation. AIM: The aim of this study was to determine the functional outcome, recurrent dislocation rate and tendon integrity after rotator cuff repair after primary traumatic shoulder dislocation. MATERIALS AND METHODS: In this retrospective case series, 23 patients (age 56.4 years ± 6.3) who underwent a rotator cuff reconstruction after primary traumatic shoulder dislocation with confirmed combination of full-thickness RCT and Bankart lesion were enrolled after a minimum follow-up of 2 years. Clinical outcome (age and gender adjusted Constant Murley Score (CMS), DASH, Rowe Score) (n = 23) and sonographic tendon integrity (n = 19) were studied. RESULTS: After a mean follow-up of 58 ± 32 months, a CMS of 85.1% ± 14.7, DASH of 14.2 ± 20.5, and Rowe Score of 82.4 ± 15.2 indicated good functional outcome. In 4 of 19 patients (21.1%) a re-tear was found during sonographic evaluation. In 3 cases (13%), a revision was performed (2 × stiff shoulder, 1 × postoperative infection). One patient had a single traumatic re-dislocation (4.3%). CONCLUSIONS: Patients undergone reconstruction of the rotator cuff following a primary traumatic shoulder dislocation can achieve good functional results and a low rate of recurrent dislocation. Postoperative tendon integrity is comparable with known data about non traumatic tears.

Low return-to-sports rate after elbow injury and treatment with radial head arthroplasty.

BACKGROUND: The aim of this study was to analyze sports participation after radial head arthroplasty among recreational athletes. METHODS: A total of 57 recreational athletes (mean age, 49 years; age range, 18-79 years) treated with radial head arthroplasty for non-reconstructible radial head fractures were included in this retrospective study. The return-to-sports rate and the time to return to sports were analyzed. The clinical and radiologic outcomes were compared between patients who returned to sports (group 1) and those who did not (group 2). RESULTS: After a mean follow-up period of 8.4 years (range, 2.5-16.4 years), 30 of 57 patients (53%) had returned to sports. The mean sports frequency significantly decreased from 5.2 ± 5.0 h/week to 2.2 ± 2.9 h/week after surgery (P < .001). In group 1, 83% of patients returned to the same sports activity whereas 17% changed to a less demanding sports activity. The mean time to return to sports was 158 days (range, 21-588 days). Patients who returned to sports had a significantly better Mayo Elbow Performance Score (MEPS) (84 ± 19 points vs. 63 ± 20 points, P < .001); Disabilities of the Arm, Shoulder and Hand score (16 ± 17 vs. 46 ± 22, P < .001); and arc of flexion (114° ± 32° vs. 89° ± 36°, P = .007). A secondary radial head prosthesis (P = .046) and MEPS lower than 85 points (P = .001) were associated with a significantly lower return-to-sports rate. No differences regarding radiographic changes were found between the 2 groups (P ≥ .256). CONCLUSION: The return-to-sports rate after radial head replacement is low. A secondary radial head prosthesis and a worse clinical outcome (MEPS < 85 points) significantly increase the risk of not returning to sports after radial head arthroplasty.

Bone morphogenetic proteins - 7 and - 2 in the treatment of delayed osseous union secondary to bacterial osteitis in a rat model.

BACKGROUND: Bone infections due to trauma and subsequent delayed or impaired fracture healing represent a great challenge in orthopedics and trauma surgery. The prevalence of such bacterial infection-related types of delayed non-union is high in complex fractures, particularly in open fractures with additional extensive soft-tissue damage. The aim of this study was to establish a rat model of delayed osseous union secondary to bacterial osteitis and investigate the impact of rhBMP-7 and rhBMP-2 on fracture healing in the situation of an ongoing infection. METHODS: After randomization to four groups 72 Sprague-Dawley rats underwent a transverse fracture of the midshaft tibia stabilized by intramedullary titanium K-wires. Three groups received an intramedullary inoculation with Staphylococcus aureus (103 colony-forming units) before stabilization and the group without bacteria inoculation served as healing control. After 5 weeks, a second surgery was performed with irrigation of the medullary canal and local rhBMP-7 and rhBMP-2 treatment whereas control group and infected control group received sterile saline. After further 5 weeks rats were sacrificed and underwent biomechanical testing to assess the mechanical stability of the fractured bone. Additional micro-CT analysis, histological, and histomorphometric analysis were done to evaluate bone consolidation or delayed union, respectively, and to quantify callus formation and the mineralized area of the callus. RESULTS: Biomechanical testing showed a significantly higher fracture torque in the non-infected control group and the infected rhBMP-7- and rhBMP-2 group compared with the infected control group (p < 0.001). RhBMP-7 and rhBMP-2 groups did not show statistically significant differences (p = 0.57). Histological findings supported improved bone-healing after rhBMP treatment but quantitative micro-CT and histomorphometric results still showed significantly more hypertrophic callus tissue in all three infected groups compared to the non-infected group. Results from a semiquantitative bone-healing-score revealed best bone-healing in the non-infected control group. The expected chronic infection was confirmed in all infected groups. CONCLUSIONS: In delayed bone healing secondary to infection rhBMP treatment promotes bone healing with no significant differences in the healing efficacy of rhBMP-2 and rhBMP-7 being noted. Further new therapeutic bone substitutes should be analyzed with the present rat model for delayed osseous union secondary to bacterial osteitis.

Interobserver and intraobserver agreement of ligamentous injuries on conventional MRI after simple elbow dislocation.

BACKGROUND: The primary objective of this study was to assess the interobserver and intraobserver agreement on ligamentous injuries on conventional magnetic resonance imaging (MRI) in acute simple elbow dislocation. The secondary objectives were to determine the interobserver agreement on the assessment of joint congruity, joint effusion, loose bodies and chondral lesions on conventional MRI. METHODS: Conventional MRIs (1.5 Tesla, elbow specific surface coil) of 30 patients (40.7 years; range 14-72) with simple elbow dislocations were evaluated by four blinded examiners. An analysis of the interobserver agreement of all raters and for several subgroups (radiologists, orthopaedics, experienced, non-experienced) was performed. The examiners assessed the integrity (intact, partial tear, complete tear) of the lateral collateral ligament (LCL), medial collateral ligament (MCL), extensor and flexor tendons, as well as the presence of joint congruity, joint effusion, loose bodies and chondral lesions. Agreement strength, correlation and proportion of exact agreement were determined for interobserver agreement, and intraobserver agreement analyses. RESULTS: Interobserver agreement of all examiners was fair to moderate for collateral ligaments (LCL: 0.441, MCL: 0.275). Exact agreement of all raters was found in 33.3% for the LCL and in 26.7% for the MCL. The both experienced examiners showed highest agreement strength for the LCL (0.619) and the radiologists showed highest agreement strength for the MCL (0.627), the proportion of exact agreement was 60.0% in both categories. A high proportion of exact agreement regarding joint congruity (90%), joint effusion (100%), loose bodies (96.7%) and chondral lesion (80%) was found among the radiologists. The evaluation of the intraobserver agreement revealed slight to substantial agreement (0.227 to 0.718) for the collateral ligaments. CONCLUSIONS: This study shows difficulties in the evaluation of ligaments by conventional MRI technique as demonstrated by a weak inter- and intraobserver agreement. This should be the basis to develop new MRI quality standards with special focus on coronal oblique reconstructions to improve the evaluation of ligament injuries after simple elbow dislocations.

Bone Incorporation of Silicate-Substituted Calcium Phosphate in 2-Stage Revision Anterior Cruciate Ligament Reconstruction: A Histologic and Radiographic Study.

PURPOSE: To evaluate the histologic and radiographic outcomes of using silicate-substituted calcium phosphate (Si-CaP) as bone graft substitute for the augmentation of tunnel defects in 2-stage revision anterior cruciate ligament (ACL) reconstruction. METHODS: Forty patients undergoing 2-stage revision ACL reconstruction were included in a prospective, randomized controlled clinical trial between 2012 and 2015. The inclusion criteria were tunnel diameter of the tibial and/or femoral tunnel of 10 mm or greater after failed ACL reconstruction. Twenty patients received autologous bone from the iliac crest and 20 patients received Si-CaP as a bone graft substitute for tunnel grafting at the first-stage procedure. Punch biopsy specimens of the augmented tunnels were taken at the second-stage procedure, and histologic examination included quantitative analysis of the area of immature bone formation, lamellar bone, and bone marrow. Radiographic analysis included determination of the filling rates of the tunnels on postoperative computed tomography scans. RESULTS: Forty patients with a mean age of 32 years (standard deviation [SD], 11.0 years) were analyzed. Histologic examination of the tunnels filled with Si-CaP showed that 15% (SD, 14%) of the area was covered with immature bone formation, 41% (SD, 10%) with well-organized lamellar bone, and 44% (SD, 8%) with bone marrow. In the control group (autologous bone), 58% (SD, 3%) of the area was covered with well-organized lamellar bone and 42% (SD, 3%) with bone marrow. Quantitative evaluation of the postoperative computed tomography scans showed a trend of better filling rates in patients with Si-CaP for the tibial tunnel (86% [SD, 17%] vs 78% [SD, 14%]; P = .131). Intraoperatively, Si-CaP was completely integrated into the original bone tunnel providing good stability for tunnel placement and tendon graft fixation comparable to autologous bone. CONCLUSIONS: Si-CaP as bone graft substitute for tunnel augmentation in 2-stage revision ACL reconstruction shows good histologic, radiographic, and intraoperative integration comparable to autologous bone. LEVEL OF EVIDENCE: Level I, prospective randomized controlled trial.

Sports activity after anatomic acromioclavicular joint stabilisation with flip-button technique.

PURPOSE: Sports activity after surgical AC joint stabilisation has not been comprehensively evaluated to date. The aim of this study was to determine rate, level and time to return to sports after AC joint stabilisation and to identify the influence of overhead sports on post-operative sports activity. METHODS: In this retrospective case series, a total of 68 patients with a high-grade AC joint dislocation (Rockwood type V) were stabilised using a single TightRope technique. Fifty-five patients (80.9 %) with median age of 42.0 (range, 18-65) years completed questionnaires regarding sports activity before and after surgery. Clinical outcome and complications were also evaluated. Forty-three patients participated in sports regularly before injury. Their sports activity was rated according to Allain, and non-overhead and overhead sports were differentiated. RESULTS: At median follow-up of 24 (18-45) months, 41 of 43 patients (95.3 %) had returned to sports. 63 % returned to the same sports activity as before injury. 16.3 % needed to adapt the type of sports to reduce demanding activities. 11.6 % reduced the frequency and 32.5 % the intensity of sports. The median time to return to sports was 9.5 (3-18) months. Overhead athletes (Allain Type III and IV) had to reduce their sports activity significantly more often (11.8 vs. 53.8 %; p = 0.011) and needed more time to return to sports (9.5 vs. 4.5 months; p = 0.009). CONCLUSION: After stabilisation of AC joint dislocation, the majority of patients returned to sports after a substantial period of time. Overhead athletes, in particular, required more time and had to considerably reduce their sports activity. The findings impact therapeutic decision-making after AC joint injury and help with the prognosis and assessment of rehabilitation progress. LEVEL OF EVIDENCE: IV.

Unstable simple elbow dislocations: medium-term results after non-surgical and surgical treatment.

PURPOSE: Determination of the appropriate treatment of unstable simple elbow dislocations is difficult and a topic of ongoing discussion. The aim of this study was to analyse the outcome and complications after surgery and conservative treatment, with special focus on post-traumatic joint laxity. METHODS: In this retrospective study, 118 consecutive patients with simple elbow dislocations underwent stability testing by fluoroscopy after joint reduction and were assigned to groups 1 (slight), 2 (moderate) or 3 (gross) depending on post-traumatic joint laxity. All patients of group 1 underwent conservative treatment, and of group 3 primary ligament repair. In patients with moderate elbow laxity, the treatment was decided individually. All patients underwent a similar functional rehabilitation programme during treatment. Clinical outcome was determined after an average of 3.4 ± 1.5 years using the Mayo Elbow Performance Score (MEPS), and treatment-associated complications and revisions were recorded. RESULTS: Forty-nine patients (41.5 %) were assigned to group 1, 41 patients (34.7 %) to group 2 and 28 patients (23.7 %) to group 3. In group 2, 22 patients underwent ligament repair, while 19 patients were treated conservatively. On average, an excellent MEPS was achieved in group 1 after conservative treatment (MEPS 95.8 ± 9.0), similar to results after ligament repair of grossly unstable elbows in group 3 (91.6 ± 11.7). Interestingly, in group 2 conservative treatment was associated with a slightly lower MEPS (90.0 vs. 95.7), and significantly fewer patients achieved an excellent MEPS (81.8 vs. 52.6 %, p = 0.045). Similarly, conservative treatment in group 2 was associated with a fivefold to sixfold risk of complications (p = 0.032) and revision surgery (p = 0.023). CONCLUSIONS: This study supports the notion that patients with slight elbow laxity can be treated non-operatively, while primary surgical treatment should be performed in patients with moderate and gross laxity to avoid post-traumatic sequelae and decrease revision rates. LEVEL OF EVIDENCE: Retrospective Cohort Study, Level III.

Development and validation of a novel questionnaire for self-determination of the range of motion of wrist and elbow.

BACKGROUND: The aim of this study was to develop and validate a novel self-administered questionnaire for assessing the patient's own range of motion (ROM) of the wrist and the elbow. METHODS: In a prospective clinical study from January 2015 to June 2015, 101 consecutive patients were evaluated with a novel, self-administered, diagram-based, wrist motion assessment score (W-MAS) and elbow motion assessment score (E-MAS). The questionnaire was statistically evaluated for test-retest reliability, patient-physician agreement, comparison with healthy population, and influence of covariates (age, gender, affected side and involvement in workers' compensation cases). RESULTS: Assessment of patient-physician agreement demonstrated almost perfect agreement (k > 0.80) with regard to six out of eight items. There was substantial agreement with regard to two items: elbow extension (k = 0.76) and pronation (k = 0.75). The assessment of the test-retest reliability revealed at least substantial agreement (k = 0.70). The questionnaire revealed a high discriminative power when comparing the healthy population with the study group (p = 0.007 or lower for every item). Age, gender, affected side and involvement in workers' compensation cases did not in general significantly influence the patient-physician agreement for the questionnaire. CONCLUSION: The W-MAS and E-MAS are valid and reliable self-administered questionnaires that provide a high level of patient-physician agreement for the assessments of wrist and elbow ROM. LEVEL OF EVIDENCE: Diagnostic study, Level II.

Increased bone formation in a rabbit long-bone defect model after single local and single systemic application of erythropoietin.

Background and purpose - Delayed bone healing with non-union is a common problem. Further options to increase bone healing together with surgery are needed. We therefore evaluated a 1-dose single application of erythropoietin (EPO), applied either locally to the defect or systemically during surgery, in a critical-size rabbit long-bone defect. Material and methods - 19 New Zealand White rabbits received a 15-mm defect in the radius diaphysis. An absorbable gelatin sponge was soaked with saline (control group and systemic treatment group) or EPO (local treatment group) and implanted into the gap. The systemic treatment group received EPO subcutaneously. In vivo micro-CT analysis was performed 4, 8, and 12 weeks postoperatively. Vascularization was evaluated histologically. Results - Semiquantitative histomorphometric and radiological evaluation showed increased bone formation (2.3- to 2.5-fold) in both treatment groups after 12 weeks compared to the controls. Quantitative determination of bone volume and tissue volume showed superior bone healing after EPO treatment at all follow-up time points, with the highest values after 12 weeks in locally treated animals (3.0- to 3.4-fold). More vascularization was found in both EPO treatment groups. Interpretation - Initial single dosing with EPO was sufficient to increase bone healing substantially after 12 weeks of follow-up. Local application inside the defect was most effective, and it can be administered directly during surgery. Apart from effects on ossification, systemic and local EPO treatment leads to increased callus vascularization.

A new animal model for delayed osseous union secondary to osteitis.

BACKGROUND: The treatment of infection-related delayed bone unions is still very challenging for the orthopedic surgeon. The prevalence of such infection-related types of osteitis is high in complex fractures, particularly in open fractures with extensive soft-tissue damage. The aim of this study was to develop a new animal model for delayed union due to osteitis. METHODS: After randomization to infected or non-infected groups 20 Sprague-Dawley rats underwent a transverse fracture of the midshaft tibia. After intramedullary inoculation with staphylococcus aureus (10(3) CFU) fracture stabilization was done by intramedullary titanium K-wires. After 5 weeks all rats were euthanized and underwent biomechanical testing to evaluate bone consolidation or delayed union, respectively. Micro-CT scans were additionally used to quantitatively evaluate the callus formation by the score of Lane and Sandhu. Blood samples were taken to analyze infectious disease markers (day 1, 14 and 35). RESULTS: Biomechanical testing showed a significant higher maximum torque in the non-infected group 5 weeks postoperatively compared with the infected group (p < 0.001). According to the Lane and Sandhu score a significantly higher callus formation was found in the non-infected group (p < 0.001). Similarly, the leucocyte count in the infected group was significantly higher than in the non-infected group (p < 0.05). CONCLUSIONS: Here we have established a new animal model for delayed osseous union secondary to osteitis. The animal model appears to be appropriate for future experimental studies to test new therapeutic strategies in these difficult to treat bone healing complications.

Establishment of a new methicillin resistant Staphylococcus aureus animal model of osteomyelitis.

PURPOSE: The increase in methicillin-resistant Staphylococcus aureus (MRSA) infections is currently a major health care problem. Vancomycin is still often the first-line anti-microbiological agent for treating such infections; however, a recent decline in efficacy of vancomycin in MRSA infections has raised concerns and accelerated the search for new antibiotics. The aim of this study was to establish a MRSA peri-implant osteomyelitis animal model for future testing of new anti-microbiological agents under typical MRSA infection conditions. METHODS: Eighteen randomised NZW-rabbits underwent a standardised surgical procedure with the insertion of a femoral bone implant. Animals were then divided into group 1 (MRSA inoculation, no antibiotics; M/N), group 2 (MRSA inoculation, Vancomyin; M/V), and group 3 (no MRSA inoculation, no antibiotics; N/N). The primary study outcome parameters were animal leucocyte count, animal weight, and animal body temperature at one, seven, and 42 days after surgery. Additionally, a histo-morphometrical score was established and adjusted to a modified histological Smeltzer score. RESULTS: Macroscopic and histo-morphometrical findings showed a peri-implant osteomyelitis in group 1 with both increased acute and chronic infection parameters in M/N, as compared to M/V and N/N, indicating that vancomycin treatment prevented typical morphological changes of MRSA peri-implant osteomyelitis. Similarly, there was a reduction in animal weight and increase in leucocyte count and body temperature in group 1 (each p < 0.005). Vancomycin treatment again resulted in significantly reduced leucocyte count and body temperature, and increased animal body weight. CONCLUSIONS: Here we have established a peri-implant MRSA osteomyelitis model that successfully combined clinical and laboratory outcome parameters of infection with histo-morphometrical results; this model appears to be valuable for future experimental use and therapeutic monitoring of new anti-microbiological MRSA drugs.

Radial head prosthesis in complex elbow dislocations: effect of oversizing and comparison with ORIF.

PURPOSE: Elbow dislocations with complex elbow instability (CEI) and unstable radial head fractures require reconstruction by open reduction and internal fixation (ORIF) if possible or alternatively by a radial head prosthesis. The aim of this study was to determine the differential outcome of both strategies and to investigate the contribution of prosthesis-related radiographic factors such as oversizing on clinical outcome. METHODS: A total of 53 patients underwent ligament and coronoid refixation, and radial head reconstruction by ORIF (n = 18; group 1) or by monopolar modular prosthesis (n = 35; group 2). Patients were followed by the Mayo Elbow Performance Score (MEPS) and a radiological score including prosthesis oversizing, joint subluxation, ossifications, capitellar erosions, implant loosening and ulno-humeral osteoarthritis. To investigate the effect of oversizing, group 2 was subdivided by prosthesis overlenghtening ≥ 2 mm. RESULTS: A total of 42 patients (79.2%) could be followed for 3.0 ± 1.3 years with an average MEPS of 76.8 ± 17.2. Patients with ORIF had slightly better MEPS (82.1 ± 9.9) as compared with group 2 (74.7 ± 19.1) though three ORIF patients required an early conversion to prosthesis. In group 2, oversizing occurred frequently and 50% showed an overlenghtening ≥ 2 mm. Oversizing significantly decreased MEPS (63.2 ± 21.3 vs 84.7 ± 9.0; p = 0.001) and elbow range of motion and increased the occurrence of other radiological abnormalities and the risk for surgical revisions. The radiological score and prosthesis overlenghtening but not prosthesis diameter showed an inverse correlation with MEPS. CONCLUSIONS: In CEI a radial head reconstruction with a prosthesis demonstrates similarly good clinical results as compared to ORIF in anatomically sized prosthesis, but prosthesis oversizing could induce other radiographic abnormalities with then deteriorated outcome.

Posttraumatic and postoperative osteomyelitis: surgical revision strategy with persisting fistula.

INTRODUCTION: Posttraumatic and postoperative osteomyelitis (PPO) with bacteria colonisation during trauma and associated surgery is an increasing clinical problem. This study investigated the treatment of PPO by surgical revision including irrigation, debridement, and temporary hardware maintenance. In addition, a drainage was inserted as persisting fistula to control osteomyelitis until fracture healing was achieved. Trauma- and osteomyelitis-related factors that influenced the study outcome were determined. PATIENTS AND METHODS: 67 consecutive patients with PPO were included. At onset of PPO, patients had incomplete fracture healing. Patients were subdivided by time of PPO occurrence (acute, subacute or chronic), initial soft tissue trauma, anatomical location, and initial fracture type (AO classification). The study outcome measures included radiographic and clinical follow-up. RESULTS: 59 patients could be followed for an average of 23 months after revision surgery. A bone healing was achieved by 89% of patients after 14.7 ± 13.4 weeks. Fractures of the lower extremity, open fractures and comminuted C-type fractures took significantly longer to achieve bone healing (p < 0.05 each). Time of PPO occurrence did not influence bone healing. After fracture consolidation, no re-infection was found. CONCLUSIONS: This study showed high rates of bone healing, indicating that this strategy with persisting fistula should be considered as alternative treatment option in patients with PPO.

Treatment of Large Femoral and Tibial Bone Defects With Plate-Assisted Bone Segment Transport.

OBJECTIVES: The purposes of this study were to assess clinical and radiographic outcomes following plate-assisted bone segment transport (PABST) in large bone defects of the lower extremities. DESIGN: Retrospective study of prospectively collected data. SETTING: Level-1 trauma center located in Germany. PATIENT SELECTION CRITERIA: Patients who underwent PABST and were at least 1 year postoperatively were included. OUTCOME MEASURES AND COMPARISONS: Demographic data were collected. Radiographic apparent bone gap (RABG), time to consolidation, time to full weight-bearing, and consolidation index were calculated. Numeric rating scale, lower extremity functional scale (LEFS), and complications were assessed. RESULTS: Fifteen patients [13 male; mean age 51 years (range, 20-75)] underwent PABST and had follow-up at a mean of 29.1 months. The tibia was affected in 8 and the femur in 7 patients. Preoperative RABG was 60 mm [interquartile range (IQR): 40-125], and bone defects were caused by septic nonunions in 73% of patients. Fourteen patients (93%) demonstrated consolidated transport callus at 7.3 months [95% confidence interval (95% CI), 6-8.5], and 9 patients (60%) demonstrated complete consolidation of both docking site and transport callus at 11.5 months (95% CI, 7.3-15.3). Postoperative RABG was 0.1 mm (IQR: 0-0.8), and consolidation index was 1.9 months/cm (95% CI, 1.3-2.5). All patients achieved full weight-bearing at 8.7 months (IQR: 6.5-10.3). LEFS was 42 (95% CI, 34-50), and numeric rating scale was 3 (95% CI, 2-4). Patients treated for tibial defects had a significantly higher consolidation rate compared with patients treated for femoral defects ( P = 0.040). CONCLUSIONS: PABST demonstrated high consolidation of transport callus with few complications. Although full weight-bearing was achieved in all patients, complete consolidation of the docking site was only present in 60% of cases. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.