Background

Prosthetic implants used in primary total hip replacements have a range of bearing surface combinations (metal-on-polyethylene, ceramic-on-polyethylene, ceramic-on-ceramic, metal-on-metal); head sizes (small <36mm, large 36mm+); and fixation techniques (cemented, uncemented, hybrid, reverse hybrid), which influence prosthesis survival, patient quality of life, and healthcare costs. This study compared the lifetime cost-effectiveness of implants to determine the optimal choice for patients of different age and gender profiles.

Summary Statement

Description of an original in vitro protocol for assessing combined bacteria and cell competitive adherence on the surface of biomaterials of medical interest

Introduction

Although femoral neck fractures remain a concern in short term failures for hip resurfacing, acetabular component position and fixation are increasingly being recognized as causes of mid term failures for hip resurfacing. This study aimed to evaluate the migration pattern of a cobalt chrome, beaded acetabular component for a metal on metal hip resurfacing.

Long-term functional and degenerative consequences of non treated slipped capital femoral epiphysis (SCFE), have been extensively demonstrated. At present, the treatment of SCFE is well described, however the treatment of the sequelae of SCFE, once osseous consolidation has happened, remains controversial.

Our aim is to describe an original technique of cuneiform osteotomy of the femoral neck through surgical hip dislocation for the treatment of sequelae of SCFE. Six hips were operated with sequelae of severe SCFE; average age of 15,2 years, whose consulting motivation was hip pain and severe limp. All of them, with bony consolidation of the femoral physis at the time of the consultation.

In all cases, it was performed a cuneiform osteotomy of femoral neck and replacement of the femoral epiphysis, through surgical hip dislocation. It was made a dissection and elevation of cervical periosteum to protect the epiphyseal vessels of the femoral head; then, the cuneiform osteotomy of the femoral neck is made with replacement of the femoral epiphysis to anatomical location and fixed.

The mean follow up was 21,2 months. We obtained consolidation in 100% of the cases, did not appear avascular necrosis nor other complications. An improvement was obtained according to Harris Hip Score from 37,6 points to 96,6. Correction of the epiphyseal-shaft angle was obtained from 62° to 12,6°.

This technique proposed in patients with sequel of SCFE is a good alternative of treatment, with good anatomical, functional, clinical and radiological results in young patients, without mid-term complications.

Introduction and objective: Distal biceps tendon ruptures commonly occur in the dominant arm of male between 40 and 60 years of age. The degenerative tendon avulses from the radial tuberosity. Conservative treatment results in decreased flexion and supination strength. Surgical reattachment is the treatment of choice and several surgical approaches and fixation devices have been proposed. The purpose of this study was to compare the results of two different techniques.

Materials and Methods: Twenty-four consecutive patients with distal biceps tendon ruptures were randomly assigned to one of two treatment groups: 12 using 2 biodegradable anchors through a modified 2-incision technique (group A) and 12 patients underwent distal biceps repair using an Endobutton^® (Acufex Smith & Nephew, Andover MA) using a single transverse anterior incision (group B). All patients were male. Average age was 40 (33–57) in groupA and 42 (29–59) in group B. The rupture was located in the dominant arm in 6 patients in groupA and 7 in group B.

The interval between injury and surgery was similar in both groups (< 12 days). Postoperative protocol and rehabilitation was the same in both groups. Full range of motion as tolerated was allowed two week after surgery.

Active range of motion, Mayo Elbow Performance Score (MEPS), pain, strength (Dexter isokinetic testing), patient satisfaction, operative time and elbow radiographs were evaluated at 12 months postoperatively. The mean follow-up was 17 months (range, 12–34).

Results: Average operative time (minutes):50 (group A) and 42 (group B). There were no complications in group B. Two patients in group A had a transient posterior interosseous nerve neurapraxia with spontaneous full recovery after 3 months, and other one developed symptomatic heterotopic bone formation and synostosis was resected. There was no statistical significant difference in MEPS score, range of motion, time to return to work or strength between both groups. All patients in both groups were satisfied with their final result and eventually returned to their pre-injury activity level without sequelae after 12.2 (group A) and 10.3 (group B) weeks.

Conclusion: Functional results of the two techniques studied were similar. Anterior approach showed lesser complications and less time off work than 2-incision technique. Endobutton^® single approach assisted tecnique should be considered the gold standard procedure for distal biceps tendon repair due to its shorter operative time and lower morbidity. However, we need series with a longer follow-up to confirm these results.

Aim: To assess the functional and occupational outcome of open elbow arthrolysis for post-traumatic contractures.

Materials and Methods: Prospective evaluation of 60 consecutive cases (86% male,14%female) of post-traumatic extrinsic elbow stiffness. Average age was 37 years (24–48). Moderate to high physical demand at work in 96% of cases. 56% of cases involved the right side.

Open arthrolysis (column procedure) trough a lateral (72%) or posterior (28%) approach followed a minimum rehabilitation period of 6 months post original injury. In 8 cases, an anterior transposition of the ulnar nerve was required. Patients received postoperative analgesia with Bupivacaine 0,0125% trough an indwelling catheter. No chemical or radiotherapy ectopic calcification prophylaxis was used. Postoperative complications, range of motion, X-ray evaluation, time to return to work, activity level and workers’ compensation were evaluated at the end of follow-up (24 months, range 12–36).

Results: Complications occurred in 14% of cases. Two patients required revision surgery for ectopic calcifications restricting prono-supination. The flexo-extension (FE) arc of motion improved from 49 ° to 115 ° and that of prono-supination (PS) from 100 ° to 158 ° The results were found to be statistically significant for FE (p= 0.054) and PS (p> 0,00001).

In 20% of cases, patients returned to their previous job with some restrictions (33% disability) and 12% changed to a less physically demanding occupation.

Conclusions: Open arthrolysis is an effective surgical procedure to improve mobility in post-traumatic stiff elbows. It is indicated when the joint interline is preserved. Good functional and occupational outcome in a high percentage of case in the working population was observed.

This work was aimed at study the role of paraspinal muscles on spinal tensegrity. Four different models of spinal tensegrity breakage with and without injury of the posterior spinal muscle were investigated.

Fifteen minipigs (mean age 6-week) underwent costotransversectomy (CTT) at 5 consecutive vertebral segments. In 4 animals ribs and transverse processes (T7–T11) were removed through a posterior midline approach with complete desinsertion of paraspinal muscles. In other 3 animals, CTT was performed by a posterolateral approach (T6–T10) without detachment of paraspinal muscles. Other 4 minipigs underwent rib resection (T7-T11) throughout a thoracoscopic approach avoiding damage of posterior spinal muscles. A final group of 4 animals, a complete detachment of the paraspinal muscles was performed from T7 to T11 without removing bony structures and leaving in deep surgical wax attached to the spinous and transverse processes to avoid reinsertion of the muscles after surgery. Anatomic specimens were radiologically and macroscopically studied just at sacrifice 5 months after surgery

All 4 animals operated on of CTT by midline posterior approach developed structural spinal deformity with curve convexity at the side of rib removal (mean Cobb angle 34,6°). Animals undergoing CTT by posterolateral approach without paraspinal muscle detachment did not develop any significant spinal deformity. Absence of spinal deformity was also found in those animals in which rib resection was performed by thoracoscopy without injury of the posterior spinal muscles. All 4 animals undergoing detachment of the paraspinal muscles without CTT and application of the surgical wax developed scoliotic curves (mean Cobb angle of 28°).

In conclusion, a new insight on the underlying pathogenic mechanisms of scoliotic curves is given by using this spinal tensegrity model. Isolated damage of the posterior muscle-ligamentous structures around the costotransverse joints breaking muscles spine tensegrity seems to be mandatory to induce scoliotic deformity. Rib removal alone appeared to have less scoliotic inductive implication. The finding questions previous knowledge on scoliosis etiopathogeny.

Introduction and purpose: We present the results of our surgical method involving nerve decompression, reduction and circumferential spinal fusion via posterior approach for severe spondylolisthesis.

Materials and methods: We studied 14 patients with spondylolisthesis and slippage greater than 50%; mean age 24. Mean slip angle 37° and mean preoperative slip 74%.

Procedure: Via a posterior approach we performed neural decompression and placed pedicle screws in L5-S1 (in one case we instrumented L4 for associated L4-L5 spondylolisthesis) and iliac screws (except in three cases). We removed the annulus fibrosus, the L5-S1 disc and the rounded proximal edge of the sacrum. Following distraction of L5-S1 we inserted bone graft cages (from 3 to 5). We adjusted the bars with spanners to reduce slippage and achieve final curvature of the spine.

The cases were monitored with evoked potentials and epidural catheter.

We studied preoperative, postoperative and final check X-rays. The clinical histories were also reviewed.

Results: One rupture of the dura. Two patients with anterior slippage of a cage. One posterior slippage of L5 screws, without revision surgery. One postoperative infection resolved by surgical cleaning and antibiotic therapy.

After mean follow-up of 32 months the radiographic study showed no pseudoarthrosis. Final mean slippage was 15% and slip angle 5°. Ten patients had no pain or physical limitations. Two presented mild lumbar discomfort and occasional limitation.

Conclusions: The procedure we used was shown to be effective in correcting the deformity with excellent clinical results.