Objectives

Effects of insulin-like growth factor 1 (IGF1), fibroblast growth factor 2 (FGF2) and bone morphogenetic protein 2 (BMP2) on the expression of genes involved in the proliferation and differentiation of osteoblasts in culture were analysed. The best sequence of growth factor addition that induces expansion of cells before their differentiation was sought.

Background: The Duraloc cup is a frequently used metal backed hemispheric porous-coated cementless acetabular cup. Published radiological data on loosening rates remain contradictory. Despite to this contradictory radiological data is the good clinical performance of this cup reported by many authors. The aim of our study was to evaluate radiological outcome (cup migration, acetabular abduction angle, cup anteversion) and possible correlation to clinical data after 12 years.

Methods: Migration analysis of 40 cementless Duraloc 100 cups (38 patients, average age 57 years, range 52 to 68years, 25 male, 13 female) could be retrospectively performed after a 12 year follow up using Einzelbild-Roentgen-Analyse (EBRA) software. An average of 5 standardised anteriorposterior radiographs (range 4 – 8) could be evaluated. Clinical outcome was assessed using HHS score. Cup migration, acetabular abduction angle, cup anteversion, heterotocpic ossification and wear were determined. Statistical evaluation was performed using Mann- Whitney - U test and correlation analysis.

Results: At 12 years follow up the average horizontal migration was 1.51 mm (range 0 to 8.5 mm) and the average vertical migration was 1.44 mm (range 0 to 4.5 mm). The average cup abduction angle was 48° (range 30° to 58°, average cup anteversion was 16° (range 12 to 25°) Average wear of the polyethylene liner at latest follow up was 1.5 mm (range 1.1 to 2.1). Harris hip score improved from average 41 (range 30 – 55) to 90 (range 77 to 95) at latest follow up. We could not find any significance difference between cup migration and gender (p > 0.05). There was no positive correlation between clinical scores and migration data found (r² = 0.01). The cup diameter however showed positive correlation with cup migration (r² = 0.8).

Conclusion: Our study shows good radiological and clinical results of the Duraloc cup after 12 years. Radiological migration data did not show any correlation with clinical results. A greater cup diameter however is a risk factor for higher migration.

Objectives: Evaluation of patients satisfaction, radiological and functional outcome in patients with trapeziometacarpal osteoarthritis after trapeziectomy with a extensor carpi radialis longus suspension.

Material and Methods: Between November 1997 and Dezember 2003, 44 patients (34 female, 10 male, average age 60 years, range 46 to 73 years) underwent trapeziectomy with extensor carpi radialis longus suspension at our institution. In 37 patients clinical and radiological outcome could be assessed after an average follow up of 7 years (range 5 to 10 years). 7 patients were lost to follow up. Preoperative range of motion, pain intensity (VAS) function and radiographs were evaluated. Postoperative patients satisfaction, using the DASH score functional and radiological outcome was determined.

Results: The average patients satisfaction was 27.8 points (range 0 – 70). Pain intensity improved from pre-operative VAS 8.5 (range 6.3 – 10) to postoperative 1.9 (range 1.2 to 4). 92 % of patients would again choose this surgical procedure. Duration of pain anamnesis was 24 months or longer in 64% of patients. After 3 months full pain relief and usage property was achieved in 62% of patients.

A free opposition was possible in 76%, radial abduction of 40° was possible in 24%, of 30–40° in 38% and of 20–30° in 35% of patients. Palmar abduction of more than 40° was possible in 68% and 30 – 40° in 32% of patients. Grip strength deteriorated in 49%, in 16% there was no difference and improved in 35% compared to the other hand. The average trapezium space lost 18% of its height compared with preoperative values.

Conclusion: Trapeziectomy with extensor carpe radialis longus suspension shows good results regarding pain relief but remarkable deterioration of strength.

Background: Although the clinical relevance still remains unclear there is an increased interest in the incidence of proximal junctional kyphosis (PJK) following posterior spinal scoliosis surgery. Several authors suppose patients with hybrid instrumentation (cranial laminar hooks, caudal pedicle screws and sublaminar wires) to be at greater risk for developing PJK. The aim of our study was to evaluate the incidence of PJK and to determine risk factors in our series of AIS patients with hybrid instrumentation after a minimum follow up of 5 years.

Methods: 60 consecutive AIS patients (56 female, 4 male, average age 16 years, range 14 to 18 years) underwent scoliosis surgery using pedicle screws caudal and laminar hooks cranial at our institution. Pre - and postoperative Cobb angle, junctional kyphosis angle, number of fused levels and upper instrumented vertebra were assessed on lateral and anteriorposterior standing long cassette radiographs after an average follow up of 8 years (range 5 to 12 years). As published by Glattes et al. proximal junction was defined as the caudal end-plate of the upper instrumented vertebra to the cranial endplate two vertebrae proximal. A Cobb angle of the proximal junction greater than 10° and at least 10° greater than preoperative was defined abnormal.

Results: Average number of fused levels was 10.2 (range 8.1 to 12.3). Average Cobb angle decreased from pre-operative 65° (range 50° to 80°) to 32° (range 22° to 40°). T 4 was the upper instrumented vertebra in 30 patients, T 5 in 18 and below T 6 in 12 patients. Average Preoperative saggital PJK Cobb was 7° (range 4° to 13°). 5 patients (12%) showed abnormal proximal junctional kyphosis angel at latest follow up (average 18°, range 14 to 28°). There was no positive correlation found between upper instrumented vertebra and abnormal PJK (r² = 0.01). A greater preoperative PJK angle however showed positive correlation (r² = 0.8).

Conclusion: Compared to literature our data show a low rate (12%) of PJK after an average follow up of 8 years. We could not find any positive correlation between upper instrumented vertebra and incidence of PJK, a preoperative increased proximal kyphosis however seems to be a risk factor for developing PJK.

Study design: Prospective clinical and radiologic study.

Objective: The purpose of this study was to investigate the risk factors for adjacent segment degeneration after posterior lumbar interbody fusion (PLIF).

Summary of Background data: Although several authors have reported the adjacent segment degeneration after lumbar or lumosacral fusion, there is no consensus regarding the risk factors for adjacent segment degeneration.

Methods: Sixty-five patients were studied after PLIF after a minimum follow up time of 6 years. Plain and flexion/ extension radiographs and MRI scans were obtained and compared to preoperative and postoperative. Progression of segment degeneration was defined as a condition in which the distinction between nucleus and annulus is lost, and the disc space is collapsed according to the grading system (Grade 1–5) described by Pfirrmann et al evaluated with T2 weighted MRI scans. Patients were divided into three groups: Group 1 with no radiological progression of disc degeneration, Group 2 with radiological progression of disc degeneration, and Group 3 with radiological progression of disc degeneration and clinical deterioration. Risk factors for progression of adjacent disc degeneration as lumbar lordosis, lordosis at the fused segment, facet sagittalization, and pre-existing disc degeneration were evaluated. The images were evaluated by two independent radiologists.

Results: Fifteen patients (23%) showed no radiological progression of disc degeneration on MRI scans and were classified into Group 1. Forty patients (62%) developed some cranial or caudal deterioration of the adjacent segment without clinical deterioration and were classified into Group 2. Ten patients (15%) required reoperation for neurological and clinical deterioration caused by cranial or caudal degeneration of the adjacent disc (Group 3). No statistically significant differences were found in lumbar lordosis, lordosis at the fused segment, facet sagittalization between each group. Patients in Group 3 showed on preoperative MRI already moderate to severe alteration of the adjacent disc (mean Grade 4) compared to Group 1 (mean Grade 2) and 2 (mean Grade 2,5) (p< 0.01).

Conclusion: After PLIF disc degeneration appear homogeneously at several levels cranial and caudal to fusion over the years in most of the patients (79%). Only pre-existing degeneration of the adjacent cranial and caudal segment is a potential risk factor for clinical deterioration caused by disc collapse.

Background: Patients with femoral head osteonecrosis usually tend to be younger and more active when compared with osteoarthritis patients. Second generation metal-on-metal THA was reintroduced to reduce poly-ethylene-induced wear debris, and therefore increase longevity of implants.

The aim of this retrospective study was to compare full blood cobalt-chrome levels, patient activity, clinical/radiological outcome and implant survival in patients with osteonecrosis and osteoarthritis after a minimum follow up of 12 years.

Methods: Full blood cobalt-chrome levels of a consecutive series of 125 patients, consisting of 40 patients (38 male, 2 female, average age 35 years, range 28 to 46 years) with osteonecrosis (ON group) and 85 patients (60 male, 25 female, average age 58 years, range 52 to 68 years) with osteoarthritis (OA group) as primary diagnosis were retrospectively compared. Patient activity level was assessed using UCLA Score and clinical outcome was evaluated using HHS. Radiological outcome and implant survival (Kaplan Meyer analysis) was determined in both groups.

Results: Patients with osteonecrosis of the femoral head showed significant higher UCLA scores when compared to OA group (4 versus 7) (p < 0.05). Despite this higher patient activity no significant difference was found between cobalt-chrome full blood levels (2.1/1.6 μg/l, ON group, 1.9/1.8 μg/l OA group, respectively) (p > 0.05). No positive correlation between patient activity, acetabular cup abduction angle and cobalt-chrome levels was found (r² < 0.01). Clinical and radiological outcome were equal in both groups. Harris hip score was 91 points in the OA and 92 in the ON group (p > 0.05). Average cup inclination angle was 47° (range 32° to 55°) and 44° (range 30° to 56°) respectively (p > 0.05). Implant survival at 12 years follow up was 96% in the OA and 97% in the ON group.

Conclusion: After a minimum follow up of 12 years, we could not find increased metal levels in osteonecrosis patients when compared to the osteoartrithis group. Regarding our clinical and radiological outcome we cannot confirm previously published reports showing suboptimal results of THA in patients with osteonecrosis. Implant survival data did not differ among both group.

Metal on metal THA seems to be an effective and safe treatment option for these patients.

Introduction: There are more than 150 different methods of surgical correction of hallux valgus deformity. In our institution there is a long tradition of SCARF osteotomy. We hereby present the longterm results of the SCARF.

Material & Methods: During the years 1995 and 1996 111 patients with 128 feet were operated on for a hallux valgus deformity by the SCARF osteotomy. Of those, 81 patients with 95 feet could be seen for follow up. The mean age at time of surgery was 50.9 (21–78) years. A clinical and radiographic examination was done.

Results: After an average time of 121.9 (107–141) months 92% of the patients were very satisfied with the result of their surgery. The VAS for pain improved from an average of 6.5 to 0.34. The AOFAS score for the forefoot improved from a preoperative average of 54.4 to a postoperative average of 91.6. The radiographic evaluation gave the following results: the preoperative HVA of 31.7° improved to an average of 16.8°; the preoperative IMA of 14.8° improved to an average of 7.6°. The preoperative average dorsal extension of the MTPI did not change very much from 48.6° to 50.6°, the preoperative plantar flexion decreased from an average of 50.6° to 15°. Two patients had to be reoperated because of a recurrent hallux valgus deformity. Five other patients had a recurrent deformity, but did not need any further surgery. We could observe 3 patients with an overcorrection where one needed another surgery. No head necrosis was seen.

Conclusion: Overall the SCARF osteotomy gave good and predictable results with a good correction of the deformity and a low potential for recurrence if applied for the right patient group.

This study relates the extent of cartilage lesions within the first metatarsophalangeal joint to hallux valgus.

We prospectively examined 265 first metatarsophalangeal joints of 196 patients with a mean age of 54.2 years at operation for the existence of cartilage lesions.

Grade I lesions were found in 41 feet (15.5%), grade II in 82 (30.9%), grade III in 51 (19.3%), grade IV in 20 (7.5%). Only 71 (26.8%) showed no cartilage lesion. Cartilage lesions were found within the metatarsosesamoid and metatarsophalangeal compartments in 66 feet (34.0%), within the metatarsophalangeal compartment in 26 (13.4%) and within the metatarsosesamoid compartment in 102 (52.6%). A statistically significant correlation was found between the grade of cartilage lesion and the hallux valgus angle, both for the changes within the metatarsophalangeal and the metatarsosesamoid joints.

Bone-marrow oedema syndrome (BMOS) of the hip gives a characteristic MRI pattern, in association with severe pain, non-specific focal loss of radiological density and a positive bone scan. In our MRI-controlled study, nine patients with non-traumatic BMOS in ten hips all had core decompression. Bone-marrow pressure measurements and intraosseous venography in five cases showed pathological values. All patients had immediate relief of pain, with return of MRI signals to normal after three months. Regular review was continued for at least 24 months with serial clinical radiological and MRI assessment. At a mean follow-up of 33 months all patients remained free of pain with normal radiographs and MR scans. The histological evaluation of undecalcified sections obtained from eight core decompressions confirmed the presence of bone-marrow oedema, with necrotic and reparative processes involving bone and marrow similar to those of early avascular necrosis but with no evidence of 'osteoporosis'. These findings support the assumption that BMOS may be the initial phase of non-traumatic avascular necrosis. In most patients BMOS will have a self-limiting course, but the duration of symptoms may be reduced by core decompression treatment.

Of 142 Chiari pelvic osteotomies for osteoarthritis in dysplastic hips, most performed by Chiari himself, we were able to review 82 and obtain information about 18 by questionnaire. All patients were over 30 years of age at operation; follow-up averaged 15.5 years. Twenty hips had undergone secondary total hip replacement. The outcome was good in 75%, fair in 9% and poor in 16%. High osteotomies all gave good results, and the result also depended on adequate medialisation. Statistics were worse for patients over 44 years of age at the time of operation. For osteoarthritis secondary to hip dysplasia, the Chiari pelvic osteotomy is an alternative procedure to early hip replacement. In contrast to intertrochanteric osteotomy, it has the advantage of facilitating the implantation of an acetabular prosthesis should arthroplasty become necessary at a later stage.