Does the pronator-sparing approach improve functional outcome, compared to a standard volar approach, in volar plating of distal radius fractures? A prospective, randomized controlled trial.

BACKGROUND: This study aimed to compare functional outcomes of a volar plate osteosynthesis for distal radius fractures (DRF) performed with either a standard volar approach (SVA), which required detachment of the pronator quadratus muscle, or a pronator-sparing approach (PqSA). MATERIALS AND METHODS: This prospective randomized controlled study included 106 patients scheduled for volar plate osteosyntheses. Patients were allocated to either the SVA group (n = 53) or the PqSA group (n = 53). Patients were blinded to treatment until completion of the study. The primary outcome measure was the Patient-Rated Wrist Evaluation (PRWE). Secondary outcome parameters were the Disabilities of the Arm, Shoulder, and Hand (DASH) score and the Modified Mayo Wrist Score (MMWS). Follow-up examinations were performed at 8 weeks and 3, 6, and 12 months postoperatively. RESULTS: Overall, 91 patients were included in the final analysis: 48 in the SVA group and 43 in the PqSA group. The two cohorts were not significantly different in demographic characteristics, including age, sex, injuries on the dominant side, type of injury, and fracture classification. We found significant differences between groups at 6 months in the mean PRWE (SVA: 12.3 ± 10.4, PqSA: 18.9 ± 14.11 points) and in the mean DASH score (SVA: 12.3 ± 11.9, PqSA: 19.3 ± 16.7 points), which favoured the SVA. We found no significant differences between groups in the MMWS or in the PRWE and DASH scores at any other time points. CONCLUSIONS: This randomized comparative clinical trial failed to demonstrate that a volar plate osteosynthesis performed with a PqSA could improve the outcome, compared to the SVA, in patients with DRF. LEVEL OF EVIDENCE: II Trial registration Comparison of Two Volar Plating Systems for Distal Radius Fractures, ClinicalTrials.gov (NCT03474445), registered 22 March 2018, retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03474445?cond=radius&cntry=AT&draw=2&rank=1.

Standard radiographic assessments of distal radius fractures miss involvement of the distal radioulnar joint: a diagnostic study.

INTRODUCTION: Distal radius fractures account for one-fifth of all fractures in the emergency department. Their classification based on standard radiographs is common practice although low inter-observer reliabilities and superiority of computer tomography (CT) scanning in evaluation of joint congruency have been reported. MATERIALS AND METHODS: We retrospectively analyzed 96 displaced distal radius fractures scheduled for open reduction and internal fixation using standard radiographic assessment. The radiographs were classified with the Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/OTA), Fernandez and Frykman classifications by three observers and inter-rater reliabilities were calculated. Additional CT scanning was performed in all cases and the following parameters were assessed: radiocarpal joint involvement, fracture extent into the radial sigmoid notch, i.e. the distal radio-ulnar joint, comminution of the metaphysis, and concomitant ulnar styloid fracture. The CT scans were used as a reference standard to determine sensitivity and accuracy of standard radiographic assessment in evaluation of distal radius fractures. RESULTS: The inter-rater agreement for the AO classification was 35.4%, 68.8% for the Fernandez and 38.5% for the Frykman classification. Fracture extension into the radiocarpal joint was present in 81 cases (84.4%). Sigmoid notch involvement was found in 81 fractures (84.4%). Involvement of both joints was present in 72 cases (75%). The sensitivity of standard radiographs regarding radiocarpal joint involvement was 93.8%. Considering involvement of the distal radio-ulnar joint the false-negative rate using standard radiographs was 61.7% and the test's accuracy for sigmoid notch involvement was 45.8%. CONCLUSION: This study demonstrates that involvement of the sigmoid notch is frequently missed in standard radiographs. The presented data support the frequent use of CT imaging to allow the holistic illustration of a fracture's complexion and to ensure optimal pre-operative planning.

Ossification of the pseudarthrosis following the Sauvé-Kapandji procedure: a case report and review of the literature.

We report a case of new onset pain and loss of forearm rotation 3 years after Sauvé-Kapandji (SK) procedure. A revision ulnar osteotomy with application of bone wax restored ROM through 17 months follow-up. A literature review of pseudarthrosis ossification after SK procedure was also performed.

Pull-out forces of headless compression screws in variations of synthetic bone models imitating different types of scaphoid fractures in good bone quality.

Screw osteosynthesis using headless compression screws has become the accepted gold standard for the surgical treatment of scaphoid fractures. Optimal screw specifications remain controversially discussed. We aimed to investigate the influence of bone model composition on screw stability tests using headless compression screws in different scaphoid fracture models. We conducted pull-out tests using Acutrak2®mini, HCS®, HKS®, HBS®, Herbert/Whipple® and Twinfix® screws. To imitate cortical and cancellous bone, two-layer polyurethane (PU) models with two distinct densities were produced. The cylinders were cut at different positions to replicate fracture localisations at increasing distances. The maximum pull-out force required to achieve up to 1 mm of pull-out distance (Nto 1 mm) was measured. Acutrak2®mini and HCS® followed by Twinfix® showed the greatest average pull-out forces. Nto 1 mm was, on average, greater in the cortico-cancellous model than in the cancellous cylinder with the Acutrak2®mini and the Herbert/Whipple® screws, while it was the least with the HBS® and the Twinfix® screws; there were also differences between the HCS® and HKS®. There were no differences between the different fracture simulations in the synthesis strength using either the HKS® or HBS®. The pull-out forces of the HCS® and Twinfix® remained high also in simulations with the smaller screw base fragments. Varying imitations of cancellous and cortico-cancellous bone and fracture localisation reveal important information about the ex vivo strength of screw syntheses. The grip of the cortical structure should be used with the screws that fit more firmly in cortico-cancellous bone.

Wrist movements induce torque and lever force in the scaphoid: an ex vivo study.

PURPOSE: We hypothesised that intercarpal K-wire fixation of adjacent carpal bones would reduce torque and lever force within a fractured scaphoid bone. METHODS: In eight cadaver wrists, a scaphoid osteotomy was stabilised using a locking nail, which also functioned as a sensor to measure isometric torque and lever forces between the fragments. The wrist was moved through 80% of full range of motion (ROM) to generate torque and force within the scaphoid. Testing was performed with and without loading of the wrist and K-wire stabilisation of the adjacent carpal bones. RESULTS: Average torque and lever force values were 49.6 ± 25.1 Nmm and 3.5 ± 0.9 N during extension and 41 ± 26.7 Nmm and 8.1 ± 2.8 N during flexion. Torque and lever force did not depend on scaphoid size, individual wrist ROM, or deviations of the sensor versus the anatomic axis. K-wire fixation did not produce significant changes in average torque and lever force values except with wrist radial abduction (P = 0.0485). Other than wrist extension, torque direction was not predictable. CONCLUSION: In unstable scaphoid fractures, we suggest securing rotational stability with selected implants for functional postoperative care. Wrist ROM within 20% extension and radial abduction to 50% flexion limit torque and lever force exacerbation between scaphoid fragments.

Introduction of a new repair technique in bony avulsion of the FDP tendon: A biomechanical study.

The purpose of this study was to determine the biomechanical characteristics of an innovative surgical technique based on a tension banding principle using a suture anchor in the repair of bony avulsions of the flexor digitorum profundus tendon. After injury simulation in 45 fresh frozen distal phalanges from human cadavers, repair was performed with minifragment screws, interosseous sutures and the innovative technique (15 per group). All repairs were loaded for a total of 500 cycles. Subsequently the specimens were loaded to failure. Load at failure, load at first noteworthy displacement (>2 mm), elongation of the system, gap formation at the avulsion site, and the mechanism of failure were assessed. The new techniques' superior performance in load at failure (mean: 100.5 N), load at first noteworthy displacement (mean 77.4 N), and gap formation (median 0 mm) was statistically significant, which implies a preferable rigidity of the repair. No implant extrusion or suture rupture during cyclic loading were recorded when the new technique was applied. This innovative repair technique is superior biomechanically to other commonly used surgical tendon reattachment methods, particularly with respect to an early passive mobilisation protocol. Further, due to its subcutaneous position, reduction of complications may be achieved.

Treatment options and outcome after bony avulsion of the flexor digitorum profundus tendon: a review of 29 cases.

INTRODUCTION: The objective of this retrospective review was to evaluate the functional and esthetic outcomes in patients with non- or minimally (<2 mm), and severely (>2 mm) displaced bony avulsions of the flexor digitorum profundus (FDP) tendon. MATERIALS AND METHODS: Between 1996 and 2010, 29 patients with a bony avulsion of the FDP tendon were treated. The displacement magnitude of the avulsed fragment determined, whether conservative or surgical treatment was performed. Persisting functional deficit, radiological findings, remaining disabilities using the Disability of the Arm, Shoulder, and Hand (DASH) score, as well as treatment-related deformities and complications were evaluated retrospectively and at a mean follow-up of 7 years. RESULTS: In 16 patients, conservative therapy by initial static splinting due to a fragment displacement of <2 mm was conducted. These patients reported no functional impairment at follow-up. In 13 cases, major displacement (>2 mm) of the bony fragment led to an open reconstruction of the avulsion injury either by screw fixation or a Lengemann pull-out wire. In a majority, an extension deficit in the DIP joint and a decrease of tip pinch strength by 25% was present at follow-up. In five patients, peri- or short-term postoperative complications occurred and in five, a nail deformity remained. DASH score revealed satisfying results after both therapeutic approaches. CONCLUSIONS: Conservative treatment in non- or minimally displaced avulsions leads to satisfying functional results. Patients receiving surgery after major fragment displacement need to be aware of a possible impaired ROM at the DIP joint. The use of the Lengemann pull-out wire may place patients at an increased complication risk and frequently induces nail deformities. LEVEL OF EVIDENCE: Therapeutic, level IV.

Rotational Stability of Scaphoid Osteosyntheses: An In Vitro Comparison of Small Fragment Cannulated Screws to Novel Bone Screw Sets.

BACKGROUND: The current standard of care for operative repair of scaphoid fractures involves reduction and internal fixation with a single headless compression screw. However, a compression screw in isolation does not necessarily control rotational stability at a fracture or nonunion site. The single screw provides rotational control through friction and bone interdigitation from compression at the fracture site. We hypothesize that osteosyntheses with novel bone screw sets (BSS) equipped with anti-rotational elements provide improved rotational stability. METHODS: Stability of osteosynthesis under increasing cyclic torsional loading was investigated on osteotomized cadaveric scaphoids. Two novel prototype BSS, oblique type (BSS-obl.) and longitudinal type (BSS-long.) were compared to three conventional screws: Acutrak2®mini, HCS®3.0 and Twinfix®. Biomechanical tests were performed on scaphoids from single donors in paired comparison and analyzed by balanced incomplete random block design. Loading was increased by 50 mNm increments with 1,000 cycles per torque level and repeated until a rotational clearance of 10°. Primary outcome measure was the number of cycles to 10° clearance, secondary outcome measure was the maximum rotational clearance for each torque level. FINDINGS: BSS-obl. performed significantly better than Acutrak2®mini and HCS® (p = 0.015, p<0.0001). BSS-long. performed significantly better than HCS® (p = 0.010). No significant difference in performance between BSS-obl. and BSS-long. (p = 0.361), between BSS obl. and Twinfix® (p = 0.50) and BSS long. and Twinfix® (p = 0.667) was detected. Within the torque range up to 200 mNm, four of 21 (19%) BSS-long. and four of 21 (19%) BSS-obl. preparations showed early failure. The same loading led to early failure in four (29%) Twinfix®, seven (50%) Acutrak2®mini and 10 (71%) HCS® of 14 screw samples, respectively. CONCLUSIONS: For both BSS and to a lesser extent for Twinfix® (as dual-component screw), higher rotational stabilities were identified in comparison to single component headless compression screws.

In vitro experimental investigation of the forces and torque acting on the scaphoid during light grasp.

The aim of this study was to measure the magnitude and direction of forces and torque within osteotomized scaphoids within cadaveric wrists during grasping movement of the hand. The mechanical contributions of clinically relevant individual wrist-crossing tendon groups were investigated. Wrists of eight forearms were immobilized in the sagittal, transverse, and coronal plane on a fixation device with unhindered axial gliding. The scaphoid was osteotomized and the fragments stabilized using an interlocking nail. The nail served as a sensor for measurement of inter-fragmentary forces orthogonal and torque around the sensor axis. Thus, torque and cantilever forces were measured which originated between the fragments through co-contraction through the activity of wrist-crossing tendons. Grasping movement of the hand induced a mean maximum torque of 0.038 ± 0.051 Nm and a force of 4.01 ± 1.71 N on the scaphoid. The isolated activation of thumb tendons resulted in a torque of 9.9 E-3 ± 7.7 E-3 Nm and a force of 1.42 ± 0.49 N. Despite immobilization of the wrist, grasping movement of the hand caused substantial forces and torque within the osteotomized scaphoid bone in varying directions and severity among different specimens. These factors may contribute to the development of nonunions and malunions in unstable scaphoid fractures through interfragmentary micromotion. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1734-1742, 2016.

A finite element analysis of two novel screw designs for scaphoid waist fractures.

The scaphoid is the most often fractured carpal bone. Scaphoid fracture repair with a headless compression screw allows for early functional recovery. The rotational stability of a single screw may be limited, having a potential negative impact on the healing process. Two novel screws have been designed to provide improved rotational stability compared to the existing ones. Using a computational finite element model of a scaphoid osteotomy, we compared the efficacy of one simple screw and the two new screws in restricting inter-fragmentary motion (IFM) in three functional positions of the wrist and as a function of inter-fragmentary compression force. The in-plane IFM was primary rotational and was better restricted by the new screws compared to the conventional one when the inter-fragmentary compression force was below 15-20 N, but provided no clear benefit in total flexion independently of the compression force. To better understand the differences in the non-compressed case, we analyzed the acting moments and investigated the effects of the bending and torsional screw stiffness on IFM. By efficiently restricting the inter-fragmentary shear, the new screws may be clinically advantageous when the inter-fragmentary compression force is partially or completely lost and may provide further benefits toward earlier and better healing of transverse waist fractures of the scaphoid.

Biomechanical characteristics of suture anchor implants for flexor digitorum profundus repair.

PURPOSE: To determine strength and failure characteristics of 2 suture anchors used to repair simulated flexor digitorum profundus avulsions during passive mobilization protocol simulation. METHODS: We simulated avulsion of the flexor digitorum profundus tendon in 30 distal phalanges from fresh-frozen human cadavers. Repair was performed with a 1.3 × 3.7 mm Micro-Mitek suture anchor (3-0 Orthocord suture) and a 2.2 × 4.0-mm Corkscrew suture anchor (2-0 FiberWire suture). All specimens were loaded cyclically from 2 to 15 N at 5 N/s for a total of 500 cycles. Samples were tested to failure at the completion of 500 cycles. Load at failure, load at first noteworthy displacement (> 2 mm), elongation of the system, gap formation at the tendon-bone interface, and the mechanism of failure were assessed. RESULTS: Suture failure at maximum load was the prevalent failure mechanism in both groups. No statistically significant difference in elongation of the tendon-suture complex was observed. The Corkscrew suture anchor showed a significantly superior performance in load to failure, load at first significant displacement, and gap formation at the tendon-bone interface. CONCLUSIONS: The significantly higher load capacity at first displacement (> 2 mm) and the significance of a lower gap formation at the repair site seem to be the most relevant clinical parameters. Based on this concept, the Corkscrew anchor may be superior biomechanically to the Micro-Mitek when considering an early passive mobilization protocol. CLINICAL RELEVANCE: The choice of an appropriate implant may influence the postoperative mobilization protocol and thereby improve currently reported success rates. Defining a biomechanically superior implant will provide an essential basis for further studies in flexor tendon repair research.

Fixation of supracondylar femoral fractures following total knee arthroplasty: is there any difference comparing angular stable plate fixation versus rigid interlocking nail fixation?

INTRODUCTION: Literature does not provide any reliable comparison between angular stable plate fixation and rigid nail fixation for stabilization of supracondylar periprosthetic femoral fractures. Thus, the purpose of this study was to compare these two implants in clinical practice relating to fracture healing, functional results and treatment-related complications. PATIENTS AND METHODS: In this retrospective study (level IV), clinical and radiographic records of 86 patients (62 female and 24 male, average age: 75.6) with supracondylar periprosthetic femoral fractures between 1996 and 2010 were analyzed. 48 patients underwent lateral plate fixation by an angular stable plate system (LISS), whereas 38 patients were stabilized by a rigid interlocking nail device. RESULTS: Sixty-four (76 %) patients returned to their pre-injury activity level and were satisfied with their clinical outcome. We had an overall Oxford outcome score of 2.21, with patients following angular stable plate fixation of 2.22, and patients after rigid nail fixation of 2.20. Successful fracture healing within 6 months was achieved in 74 (88 %) patients. Comparing between plate fixation and nail fixation, statistical analysis did not reveal any significant differences. Overall, we had a relatively high rate of fracture healing and a satisfactory functional outcome with both implants. Both methods of fixation showed similar results relating to the functional outcome and individual satisfaction of the patients. However, with regards to fracture healing and treatment-related complications, intramedullary nail fixation showed slight advantages.

Finite element based estimation of contact areas and pressures of the human scaphoid in various functional positions of the hand.

The scaphoid is the most frequently fractured carpal bone. When investigating fixation stability, which may influence healing, knowledge of forces and moments acting on the scaphoid is essential. The aim of this study was to evaluate cartilage contact forces acting on the intact scaphoid in various functional wrist positions using finite element modeling. A novel methodology was utilized as an attempt to overcome some limitations of earlier studies, namely, relatively coarse imaging resolution to assess geometry, assumption of idealized cartilage thicknesses and neglected cartilage pre-stresses in the unloaded joint. Carpal bone positions and articular cartilage geometry were obtained independently by means of high resolution CT imaging and incorporated into finite element (FE) models of the human wrist in eight functional positions. Displacement driven FE analyses were used to resolve inter-penetration of cartilage layers, and provided contact areas, forces and pressure distribution for the scaphoid bone. The results were in the range reported by previous studies. Novel findings of this study were: (i) cartilage thickness was found to be heterogeneous for each bone and vary considerably between carpal bones; (ii) this heterogeneity largely influenced the FE results and (iii) the forces acting on the scaphoid in the unloaded wrist were found to be significant. As major limitations, accuracy of the method was found to be relatively low, and the results could not be compared to independent experiments. The obtained results will be used in a following study to evaluate existing and recently developed screws used to fix scaphoid fractures.

Seymour fractures: retrospective analysis and therapeutic considerations.

PURPOSE: To analyze the management of Seymour fractures (juxta-epiphyseal fractures of the terminal phalanx of the finger in conjunction with flexion deformity at the fracture site, laceration of the nail bed, and frequently ungual subluxation) and to determine clinical and radiographic results following operative or conservative treatment. METHODS: Clinical and radiological results of 24 skeletally immature patients (7 girls and 17 boys; mean age, 8.5 y) with Seymour fractures were evaluated. Assessment after a mean follow-up of 10 years (range, 1-18 y) included the range of motion, the modified Kapandji index, growth disturbance of the effected digit and nail, pain according to the visual analog scale, and patients' satisfaction. RESULTS: Nine patients received nonoperative treatment. Operative management included debridement, open reduction, and fixation in 9. Owing to instability, an additional K-wire passing across the distal interphalangeal joint was used in 5. In 1 patient, the nail was removed. All surgically treated patients received a splint and perioperative cephalosporin. Twenty-three patients out of 24 gained full motion (mean, 80°; range, 65°-90°). The average modified Kapandji index was 5.0 for extension and 4.8 for flexion. Long-term minor growth disturbance of the distal phalanx (seen on radiographs at high amplification only) and nail were noted in 5 patients, and solitary nail dystrophies were observed in 6 patients. Nine of the 11 nail growth irregularities were not a relevant cosmetic problem for the patients. Patients' satisfaction assessment revealed a good clinical outcome. There was neither flexion deformity nor infection in our collective. At the 1-year follow-up examination, the average visual analog score was 0.6 (range, 0-2). CONCLUSIONS: According to the literature, the Seymour fracture is an often-underestimated injury, and open cases are prone to infection. Evaluation of the outcome in our collective demonstrated good results with the treatment approaches described. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Anatomy and variants of the triangular fibrocartilage complex and its MR appearance at 3 and 7T.

Due to the small size and complexity of its constituents, the triangular fibrocartilage complex (TFCC) has been a challenging structure for magnetic resonance (MR) imaging. Higher-field MR units, at 3T and 7T, with increased spatial resolution and the development of novel MR sequences, are promising tools for an improved visualization of the ulnocarpal complex. Anatomically, the TFCC consists of the TFC proper, the ulnomeniscal homolog, the ulnar collateral ligament, the ulnotriquetral and ulnolunate ligament, and radioulnar ligaments at the volar (palmar) and the dorsal side, as well as the sheath of the extensor carpi ulnaris tendon and the capsule of the distal radioulnar joint. This article describes the normal anatomy of the TFCC and its appearance on high-field MRI. Anatomical variants, such as the positive ulnar variance, and changes during pronation and supination are addressed.

Surgical vs nonoperative treatment of Hadley type IIA odontoid fractures.

BACKGROUND: Type II odontoid fractures with additional chip fragments are rare in clinical practice, accounting for < 10% of all odontoid fractures. Hadley et al were the first to describe these fractures as an individual subtype (IIA). OBJECTIVE: To analyze the outcome of patients after surgical or nonoperative treatment of Hadley type IIA odontoid fractures. METHODS: We analyzed the records of 46 patients at an average of 64 years of age at the time of injury. Twenty-five patients underwent surgical stabilization by anterior screw fixation and were entered into study group A; 21 patients were treated nonoperatively by halo vest immobilization and included in study group B. RESULTS: Thirty-seven patients (84%) returned to their preinjury activity level and were satisfied with their treatment. Using the Cervical Spine Outcomes Questionnaire to quantify the clinical outcome, we had an overall outcome score of 21.8. We did not find a significant difference in the overall clinical outcome between study groups. Bony fusion was achieved in 35 patients (80%). We had a nonunion rate of 13% after anterior screw fixation and a significantly higher rate of 30% after halo vest immobilization. Failure of reduction or fixation occurred in 12 patients (27%), with a significantly higher failure rate after halo vest immobilization. CONCLUSION: Hadley type IIA odontoid fractures are inherently unstable and impede proper realignment. These fractures have a significantly increased risk for secondary loss of reduction and bony nonunion, particularly after nonoperative management. Early surgery should be considered to avoid further complications.

Cementless two-staged total hip arthroplasty with a short term interval period for chronic deep periprosthetic infection. Technique and long-term results.

BACKGROUND: The two-staged exchange with delayed reimplantation is the most reliable method to treat a deep periprosthetic infection after a total hip arthroplasty (THR). Nether uniform recommendations for the technique of cementless reimplantation, nor long term clinical and radiological results are reported. MATERIALS AND METHODS: Our protocol is performed under short term antibiosis with cementless primary porous hip implants to treat chronic deep periprosthetic infections following THR. A retrospective study was performed to evaluate the clinical and radiological long term outcome and the rate of persistent infection of 14 patients. RESULTS: In a five year minimum follow up persistent infection was observed twice in a two-staged revision THR. A dislocation of the hip components was observed in three cases, and could be surgically treated in twice and by wearing a hip-brace in one case. We could not find a loosening of THR components. Three patients had a good or excellent, 11 patients a fair or bad functional outcome. There was a significant correlation between functional outcome and length of interval of prosthesis exand reimplantation. CONCLUSION: Patients have an increased comfort resulting from a short, CRP depending time interval between ex- and reimplantation. Functional outcome is the better the shorter the interval is. The reinfection rate is comparable to those of cemented revision THR's with a long term interval. We could observe advantages in a reduced amount of bone loss and better osseous integration of the uncemented implants, compared to cemented implants reviewing literature. Alterations of acetabular bone stock and soft tissue are responsible for a high rate of instability of the THR. An inaccurate gait pattern is caused by gluteal weakness in the majority of patients. Repeated surgical intervention and duration of immobilization have to be minimalized.

Gait analysis of patients with resurfacing hip arthroplasty compared with hip osteoarthritis and standard total hip arthroplasty.

Patients with standard total hip arthroplasties may have reduced hip abduction and extension moments when compared with normal nonosteoarthritic hips. In comparison, patients after resurfacing total hip arthroplasty appear to have a near-normal gait. The authors evaluated temporal-spatial parameters, hip kinematics, and kinetics in hip resurfacing patients compared with patients with unilateral osteoarthritic hips and unilateral standard total hip arthroplasties. Patients with resurfacing walked faster (average 1.26 m/s) and were comparable with normals. There were no significant differences in hip abductor and extensor moments of patients with resurfacing compared with patients in the standard hip arthroplasty group. This study showed more normal hip kinematics and functionality in resurfacing hip arthroplasty, which may be due to the large femoral head.

Unplanned 10-year retention of an external fixator for a proximal tibial fracture.

A 45-year-old homeless male patient did not return for follow-up for routine removal 72 days after an external fixator had been placed for a grade II open fracture of the proximal tibia. Ten years later, he was accidentally referred to our institution for newly incurred fractures of the femoral neck on the same side and also for an opposite-side medial malleolus fracture. The patient was still homeless, with signs of poor personal hygiene, but the original external fixator was in place. Union of his previous proximal tibia fracture had occurred, and there were no signs of any pin-tract infection. Possibilities for this successful outcome include fracture stability, subsequent healing without pin breakage, and 7 weeks of professional wound care before the patient's initial discharge from the hospital, resulting in a scarred skin barrier at the pin-skin interface.

[Stabilization of proximal humeral fractures with the intramedullary dynamic titanium helix wire]. / Die Stabilisierung von proximalen Humerusfrakturen mit der intramedullären Titanwendel Helix-Wire.

The implant Helix-Wire is a treatment device that is used since 1997. It provides minimally invasive stabilization of subcapital humeral fractures. The implant is inserted through a small lateral entrance and a cortical hole drilled into the intramedullary space of the proximal humeral shaft and drilled into the humeral head for fracture stabilization. After careful preoperative planning and successful repositioning of the fracture the technique can be performed without difficulty. A review of 35 patients with subcapital humeral fractures, who were operated using the titanium wire helix between 1998 and 2000, was carried out. Clinical and radiological results were documented. After an average time of 11.5 months 13 patients were examined according to the Constant Score: 5 good or excellent, 4 fair and 4 bad results were achieved. We conclude that this implant provides sufficient stabilization of subcapital humeral fractures classified as AO 11 A2, 11 A3.1, 11A3.2, 11B1.1, 11B1.2. It does not offer an advantage for the treatment of unstable fractures with multiple fragments or cancellous bone deficiency (11 A3.3, 11 B2.2, 11 B2.3).