The Combination of Modified Mitchell’s Osteotomy and Shortening Oblique Osteotomy for Patients with Rheumatoid Arthritis: An Analysis of Changes in Plantar Pressure Distribution

The present study aims to evaluate changes in plantar pressure distribution after joint-preserving surgery for rheumatoid forefoot deformity. A retrospective study was performed on 26 feet of 23 patients with rheumatoid arthritis (RA) who underwent the following surgical combination: modified Mitchell’s osteotomy (mMO) of the first metatarsal and shortening oblique osteotomy of the lateral four metatarsals. Plantar pressure distribution and clinical background parameters were evaluated preoperatively and one year postoperatively. A comparison of preoperative and postoperative values indicated a significant improvement in the visual analog scale, Japanese Society for Surgery of the Foot scale, and radiographic parameters, such as the hallux valgus angle. A significant increase in peak pressure was observed at the first metatarsophalangeal joint (MTPJ) (0.045 vs. 0.082 kg/cm2; p < 0.05) and a significant decrease at the second and third MTPJs (0.081 vs. 0.048 kg/cm2; p < 0.05, 0.097 vs. 0.054 kg/cm2; p < 0.05). While overloading at the lateral metatarsal heads following mMO has been reported in previous studies, no increase in peak pressure at the lateral MTPJs was observed in our study. The results of our study show that this surgical combination can be an effective and beneficial surgical combination for RA patients with mild to moderate joint deformity.

Biomechanical assessment of different fixation methods in mandibular high sagittal oblique osteotomy using a three-dimensional finite element analysis model

With modern-day technical advances, high sagittal oblique osteotomy (HSOO) of the mandible was recently described as an alternative to bilateral sagittal split osteotomy for the correction of mandibular skeletal deformities. However, neither in vitro nor numerical biomechanical assessments have evaluated the performance of fixation methods in HSOO. The aim of this study was to compare the biomechanical characteristics and stress distribution in bone and osteosynthesis fixations when using different designs and placing configurations, in order to determine a favourable plating method. We established two finite element models of HSOO with advancement (T1) and set-back (T2) movements of the mandible. Six different configurations of fixation of the ramus, progressively loaded by a constant force, were assessed for each model. The von Mises stress distribution in fixations and in bone, and bony segment displacement, were analysed. The lowest mechanical stresses and minimal gradient of displacement between the proximal and distal bony segments were detected in the combined one-third anterior- and posterior-positioned double mini-plate T1 and T2 models. This suggests that the appropriate method to correct mandibular deformities in HSOO surgery is with use of double mini-plates positioned in the anterior one-third and posterior one-third between the bony segments of the ramus.

Treatment of Radius Curvus in a Young Dog with Association of Radial Physeal Stapling, Ulnar Ostectomy and Transarticular Dynamic External Fixator Techniques

Background: Radius curvus is a clinical manifestation of the premature closure of the distal ulnar physis and the most common physeal disease in dogs, representing 63% of all physeal injuries. There are few reports indicating the technique of stapling for treatment of radius curvus in squeletically immature dogs. The aim of this study is to report a case of radius curvus in a young dog successfully treated with a combination of 3 surgical tecniques: 1- Stapling the medial and cranial portions of the distal radial physis; 2- Oblique osteotomy of the proximal ulna and ostectomy of the distal ulna, and 3- Dynamic external skeletal fixation in the elbow joint.Case: A 5-month-old female dog was referred to the University Veterinary Hospital with a history of left thoracic limb deformity for 2 weeks. There was a history of possible traumatic event on the front limb, in addition to providing nutritional supplements daily. In the radiographic evaluation the changes were identified in the left thoracic limb: shortening of the ulna, procurvatum and medial angulation of the distal radius, increased joint space and articular incongruity of the elbow joint. The dog was subjected to surgical treatment by the combination of three main surgical techniques. For the stapling of the distal radial physis the surgical approach on the cranial-medial surface of the distal radius was made. Two surgical staples were positioned in the distal radial physis. Thereafter a caudal approach was made to the distal region of the ulnar diaphysis for the distal ostectomy of the ulna. A bone segment of 1 cm in length of the distal ulnar diaphysis was removed. Another caudal approach was made to the proximal region of the ulnar diaphysis and a proximal oblique osteotomy of the ulna was performed. For the dynamic external skeletal fixation in the elbow joint two Steinmann pins were inserted. The first pin was proximal to the supracondilar foramen of the humerus and the second pin was caudal to the trochlear notch of the ulna, both parallel to the joint surface. To create a dynamic system, the pin tips were connected with elastic rubber bands on the medial and lateral sides of the elbow joint. Clinical and radiographic revaluation were made at 15, 30 and 60 days after surgery. Total correction of the limb deviation was achieved at 60 days postoperative. Two years after the surgical procedure, the owner was contacted and reported that the dog was very well and with no change in the operated limb.Discussion: The most common cause of premature closure of the distal ulnar physis is trauma. Due to the proper conical shape of the distal ulnar physis, there is more predisposition to the compression of the germinative cells in traumatic events, leading to radius curvus disease. Another cause of the radius curvus is the nutritional disbalances. In the reported case the patient had both predisponent factors, although unilateral limb involvement suggested trauma with primary causative agent. The treatment included the interruption of the supplementation of the diet associated with surgical techniques. The stapling of the distal radial physis is usually indicated for mild angular valgus deviation. In the current case the technique was applied with success regardless of the higher grade of radial deviation. Generally, the ulnar ostectomy is preferred to the osteotomy, since it reduces the rate of ulnar osteosynthesis, ensuring that the restrictive effect of the ulna upon the radial growth does not restart. In the reported case the ulnar ostectomy was associated with ulnar osteotomy to achieve a more effective result. Furthermore, the proximal ulnar osteotomy is usually indicated when elbow subluxation is present. In the current case the joint congruence was improved with the use of the dynamic external skeletal fixator.

Weightbearing Computed Tomography and 3-Dimensional Analysis of Mobility Changes of the First Ray After Proximal Oblique Osteotomy for Hallux Valgus

Background: Hypermobility of the first ray has been evaluated using various methods and has conventionally been considered to be involved in the pathology of hallux valgus. We hypothesized that hypermobility of the first ray in hallux valgus could be decreased by simply correcting foot alignment without arthrodesis. This study sought to evaluate first-ray mobility using weightbearing computed tomography (CT) before and after proximal oblique osteotomy and also in healthy volunteer’s feet. Methods: Subjects were 11 feet of 11 patients with primary hallux valgus who underwent surgery with a plantarly applied anatomic precontoured locking plate and 22 feet of 11 matched healthy volunteers. We performed nonweightbearing and weightbearing (using a load equivalent to body weight) CT scans using an original loading device preoperatively and 1-1.5 years postoperatively. Three-dimensional displacement of the distal bone relative to the proximal bone was quantified for each joint of the first ray by comparing nonweightbearing and weightbearing CT images. Results: At baseline, there were significant differences in hallux valgus angle ( P < .001) and 1-2 intermetatarsal angle ( P < .001) between healthy volunteer’s feet and preoperative hallux valgus feet. Hallux valgus angle ( P < .001) and 1-2 intermetatarsal angle ( P < .001) differed significantly between before and after surgery. All first ray joint displacement under loading decreased postoperatively to within 2° of that in healthy volunteer’s feet and showed no significant difference between postoperatively hallux valgus feet and healthy volunteer’s feet ( P > .05). Conclusions: We found that first metatarsal osteotomy even without arthrodesis corrected deformity and decreased mobility of the first ray after hallux valgus surgery. Level of Evidence: Level III, case-control study.

A Study Comparing the Outcomes of Transverse Ulnar Shortening Osteotomy Fixed with a DCP to Oblique Osteotomy Fixed with a Procedure Specific Plate

Background: Ulnar shortening osteotomy (USO) is a well-established procedure for ulnar impaction syndrome. Various types of osteotomies have been described. Methods: A retrospective cohort study was conducted to compare the results of transverse osteotomy (TO) fixed with a small fragment dynamic compression plate (Synthes, Pennsylvania, USA), to oblique osteotomy (OO) fixed with a procedure specific plate and instrumentation system (Acumed LLC, Oregon, USA). A total of 39 patients underwent TO and 62 patients underwent OO between 2007 and 2016. The main outcomes compared were rate of union, duration of radiological healing, implant removal rate and other complications. Results: The two groups were comparable with regards to demographics, side operated and smoking status (p > 0.05). Amongst the TO group; 36 out of 39 patients (92.3%) achieved union, 3 patients (7.7%) developed non-union. Six out of the 36 healed TO (16.6%) required removal of hardware due to implant-related pain. No other complications were recorded amongst TO group needing surgical intervention. Amongst the OO group, 2 of the early cohort of 62 patients (3.2%) sustained acute failure of the metalwork due to technical error. One of the remaining 60 patients (1.6%) developed non-union giving an overall union rate of 95.2%. Two patients out of 59 healed OO (3.3%) required removal of hardware. Conclusions: Although there were 2 early failures, there was a trend towards improved union rate with OO, but this did not reach statistical significance (p > 0.05). There was a significantly higher hardware removal rate recorded in TO group (p = 0.023). The OO showed shorter duration for radiological healing than TO (p < 0.05). USO performed with an OO and fixed with procedure specific plate has lower implant removal rate, a shorter duration for radiological healing and comparable union rate to TO fixed with DCP, but needs careful attention to detail.

An oblique osteotomy is better for subtrochanteric shortening in total hip arthroplasty for high hip dislocation: a mechanical comparison of four techniques

Background: Subtrochanteric femoral shortening is used during total hip arthroplasty for high hip dislocation in developmental dysplasia of hip patients. Methods: We mechanically tested the stability of various commonly used subtrochanteric osteotomy techniques. As the equivalent of a femoral stem placed in a shortened femur without any stable fixation at the osteotomy line, 2 polyvinylchloride pipes were loosely intertwined. 4 different osteotomies (Z-subtrochanteric osteotomy, oblique-45° osteotomy, double Chevron-90° and 120° subtrochanteric osteotomy) were simulated. Torsional and axial loads were applied, and torsional stiffness was calculated for each test model. Results: Z, double Chevron-90° and 120° subtrochanteric osteotomy models demonstrated lower mean torsional stiffness than oblique-45° osteotomy. With the highest torsional stiffness oblique-45° provides the best stability for treatment of high dislocation hips when a subtrochanteric osteotomy is added. Conclusions: This matches our previous clinical experience. Oblique osteotomy may also provide higher contact surfaces in the osteotomy lines to promote bone healing.