Introduction: Although a number of methods have been described to treat recurrent dislocation following total hip arthroplasty, this complication remains a challenging problem. The purpose of this retrospective study was to evaluate the minimum 2-year outcome in a consecutive series patients treated with a cemented tripolar unconstrained acetabular component for recurrent dislocation.

Patients and Methods: Fifty-one patients presenting with recurrent dislocation following primary or revision total hip arthroplasty in the absence of an identifiable curable cause were treated with a cemented tripolar unconstrained acetabular component. There were thirty-nine females and twelve males with a mean age at the time of the index procedure of 71.3 years. A single acetabular component design was used consisting of a stainless steel outer shell with grooves for cement fixation with a highly polished inner surface. This shell articulated with a mobile intermediate component with an opening diameter smaller than the 22.2-mm femoral head. No locking ring or other mean of constraint was associated.

Results: Of the fifty-one patients, forty-seven have had complete clinical and radiological evaluation data at a mean follow-up of 31.2 months (twenty-four to 56.3 months). The cemented unconstrained tripolar acetabular component restored complete stability of the hip in forty-nine patients (96%). The mean Merle d’Aubigné hip score was 15.8 ± 2.0 at the latest follow-up. Radiographic analysis revealed no or radiolucent lines less than 1 mm thick located in a single acetabular zone in forty-three of forty-seven hips (91.5%). The cumulative survival rate of the acetabular component at 36 months using revision for dislocation and/or mechanical failure as the end point was 93.3 ± 4.6% (95% confidence interval, 84.4% to 100%).

Conclusion: A cemented tripolar unconstrained acetabular component was highly effective in the treatment of recurrent dislocation with none of the complications associated with constrained devices. However, because longer term follow-up is needed to warrant that dislocation and loosening rates will not increase, the use of such a device should be limited to strict indications.

Competence of the extensor mechanism is the major determinant of functional outcome after resection of the proximal tibia and tumor prosthesis implantation. Restoration of a compromised active extension of the knee and an extension lag still remains a difficult challenge. Various techniques have been proposed in the past twenty years including direct attachment of the patellar ligament to the prosthesis, transposition of the medial gastrocnemius muscle possibly associated with other muscle flaps, transposition of the fibula and combination of these techniques. Transposition of the fibula was first reported by Kotz in 1983 but not sufficiently described, so that surgeons who want to plane and manage such a procedure can have some difficulties. We present our technique of fibula transposition and report the functional results about seven patients treated for high-grade sarcomas of the proximal tibia. Fibula transposition is carried out only if the entire fibula and its soft-tissues can be preserved. Resection of the tumor and reconstruction is carried out using the same anteromedial approach. After implantation of the prosthesis, the fibula and its muscles are mobilized anteriorly in a ‘baionnette’ shape obtained by performing a two-level osteotomy. The peroneal nerve and the anterior tibial vessels are previously identified and released to prevent tension on these structures during transposition. Care must be taken to preserve as much as possible the muscular insertions on the fibula so that probability of bone fusion increases. The biceps tendon and the lateral collateral ligament inserted in the fibular head are sutured to the patellar ligament. The knee is immobilized in a knee-ankle orthosis for 6 weeks. We have performed this technique in seven cases. A medial gastrocnemius muscle flap was associated in 3 cases to cover the prosthesis. Fusion was achieved in all cases. Full active extension was obtained in all cases with an extensor strength rated 5/5. All patients were ambulatory without external support at the last follow up.

Purpose of the study: Revision total knee arthroplasty with major destruction of bone and ligament tissue raises the problem of choosing between a complex reconstruction with a semi-constrained prosthesis or a much more simple procedure using a hinged prosthesis which transmits all of the stress to the bone anchors. The choice is basically one of longevity of the bony fixation of these constrained prostheses (and the deterioration of the articulated pieces). The present work reports the long-term outcome observed with constrained hinged prosthesis with a cemented press-fit stem implanted for bone tumors where the stress is even greater than for revisions.

Material and methods: The series included 32 prostheses implanted in young active subjects (mean age 33 years). A hinged, non-rotating Guepar II revision prosthesis was implanted. The part of the implant corresponding to the reconstruction after tumor resection was custom-made but the part implanted in «healthy» bone (for example the tibial piece in a patient with a femoral tumor) was the same as used for revisions prostheses inserted after loosening. On the healthy side, press-fit quadrangular stems were used, generally adapted to the endosteum by reaming. The prosthesis was fixed by simple mechanical adjustment before cementing, using the French paradox system (JBJS 2003). Before 1993, a metal-polyethylene bearing was used and after 1993 a metal-on-metal bearing without inserts.

Results: Among the 32 patients with a malignant tumor, 19 survived, seven with 2–10 years follow-up and 12 with 10–21 years follow-up. For the overall series, there was only one case of osteolysis on a tibial tumor which was revised at 12 years. There was one infection (hematogeneous) at 21 years (antibiotic cement). Prostheses with polyethylene inserts produced laxities or synovitis with 50% requiring synovectomy and insert replacement. There were no cases of synovitis for the metal-on-metal bearings. Two stems (inserted in adolescents) were too thin and had to be changed because of fracture without loosening.

Discussion: Prosthesis survival was 88% at ten years (1 osteolysis, 2 fractures on tumor), even for the constrained prostheses, even for young and active subjects.

Conclusion: The very good longevity of cemented pressfit stems (and the absence of synovitis and osteolysis with metal-on-metal bearings, and the low rate of infection) should be kept in mind as a possible alternative to very complex and possibly less predictable procedures in the presence of certain very severe loosenings with bone and ligament destruction.

Purpose: A consecutive series of 32 metaphyseal locked hydroxyapatite coated stems were reviewed at a maximum 5 years to analyse the effect of the type of distal (diaphyseal) and proximal (metaphyseal) fixation on clinical and radiological outcome (distal shaft fixation: tight or moderate; hydroxyapatite coating: complete or limited to metaphysic; approach: window or endofemoral).

Material and methods: Stems were used to treat femoral osteolysis (35% SOFCOT stage III and IV femoral loosening) with significant acetabular osteolysis (59% segmentary osteolysis and 47% revisions with structural allografts). Nineteen stems were implanted with a femoral window and 13 via endofemoral access. Twenty-six were screw locked. To study the effect of the type of fixation on clinical and radiographic outcome, we studied metaphyseal “regeneration”, and intraoperative diaphyseal anchorage. Anchorage was considered tight when the endosteum and the stem were in contact over at least 40 mm, and the difference in diameter between the stem and the endosteum was 1 mm or less. Anchorage was considered moderate when the height of contact was less than 40 mm and the endosteumstem difference in diameter was greater than 2 mm.

Results: The results were encouraging, with a clinical score (PMA) of 15/18, and stable diaphyseal fixation of the prosthesis in 31 hips (one migration of about 1 cm with secondary blockage in one non-locked stem). There were few complications: no infections, one isolated dislocation, one screw fracture, but three replacements of overly long stems, one trochanteric non-union which was not reoperated. In 22 hips with more than one year follow-up, shaft fixation of the stem was complete (no osteolytic lucent line), and a line of bone densification (particularly in hips with less solid anchorage) was seen in ten hips. There appeared to be bone regeneration around the hydroxy-apatite metaphysis in 50% of the cases. There were no cases of secondary osteolysis. This “regeneration” did not appear to be different after window or endofemoral replacement. It was the same with tight (63% of hips) or moderate anchorage. There was no stress shielding even when the distal stem was coated with hydroxyapatite.

Conclusion: It appears that good results can be obtained at mid-term with this type of prosthesis using a short distal (60 mm) fixation, limiting the diaphyseal escalation and requirement for femoral window.

Purpose: Reconstruction using a revascularised fibula has advantages in terms of remodelling the transplant to the stress forces and of better resistance against infections. Osteosynthesis offers mechanical advantages (stabilisaton facilitating primary and stress fracture healing) but with the risk of preventing hypertrophy of the fibula which is not exposed to the stress forces.

Material and methods: Our series of 25 vascularised fibular transfers (maximum follow-up 15 years) concerned post-trauma tissue loss (11 cases) and tumour resections (14 cases). For this study of remodelling, we retained only oncological reconstructions because in the event of trauma sequelae, many factors can interfer (infection, preservation of the homolateral fibula with tibial tissue loss). None of the patients were lost to follow-up and remodelling was assessed at two years or more.

Results: There was one failure requiring leg amputation (infected nonunion of the distal tibia on a radiated osteo-sarcoma). All the other fibulae healed. Three metaphyseal resections of the distal femur were assembled with a lateral plate using the fibula as a medial strut under compression. This type of assembly favours remodelling and excellent results were obtained in three cases. Five arthrodeses of the knee were performed using a fibula with a femorotibial nail. Healing was slow and the fibula thickened little, particularly when it was simply apposed on the tutor (three cases) rather than encased under compression (two cases). For five proximal humeri, use of a thin plate in three cases (forearm plate) was sufficient to allow healing without inhibiting remodelling.

Discussion: For the lower limb, good remodelling is obtained with an assembly allowing compression of the fibula placed medially to the shaft alignment. For metaphyseal loss, we advise a lateral plate with a fibular strut medially. For arthrodesis, a nail is probably more prudent. The position of the lateral tutor decreases the stress on the fibula and is recommended less than the medial strut position. For the humerus, synthesis is required but may be minimal to allow optimal remodelling.

Conclusion: Vascularised fibula transfer is a reliable technique which can be recommended for major resections (mean 160 mm) in active subjects. Axial compression forces applied to the graft and use of light osteosynthesis appear to favour healing and remodelling.

Purpose: In 1996, we reported the results of 65 coracoid blocks for chronic anterior instability. We found 6% true recurrence and 34% persistent apprhension. In order to improve these results, we modified our operative technique, associating capsuloplasty in the event of hyperlaxity. The purpose of the present work was to assess mid-term results.

Material and methods: Eighty-eight coracoid blocks were performed between 1995 and 2000 by the same operator. In 41 cases, the classical technique was used. In 47 cases we associated capsuloplasty. The indication for surgery was documented recurrent instability in all cases, with radiographic, MRI or endoscopic confirmation of an anteroinferior capusloligament lesion. Capsuloplasty was associated if signs suggested hyperlaxity: self-reducing dislocation, absence of notch, external rotation arm to body (RE1) greater than 80°, presence of a significant groove, laxity of the inferior flap of a T capsulotomy. Mean patient age was 24 years (14–42) and mean follow-up was 40 months (24–60). Clinical results were assessed with the Duplay criteria and three x-rays were obtained (standard AP, Lamy lateral view and glenoid lateral view).

Results: Eighty-five percent of the patients achieved a good or very good result according to the Duplay criteria. Eighty-eight percent of the blocks held without modification and 12% developed osteolysis. There were no cases of degeneration. One patient experienced recurrent dislocaion. The rate of persistent apprehension declined (12%) compared with our earlier experience. This improvement was achieved at the cost of greater loss of RE1 in the group with capsuloplasty (−20° versus −8°), but without impact on sports activity (82£% returned to their sports activities including 72% at the same level without significant difference between the groups with and without capsulotomy).

Discussion: These results demonstrate that capsuloplasty is warranted if there are signs of hyperlaxity. This technique allowed us to improve results concerning recurrence and persistent apprehension at the cost of less mobility but without effect on sports activities. We detail the objective criteria used to define hyperlaxity and describe the usual clinical expression of radiographic, arthroscopic, and arthroscopic findings.

Purpose: A spacer can be used for two-phase replacement of an infected total hip prosthesis. The goal is to facilitate reimplantation by avoiding soft tissue retraction. Several types of spacers can be used. We searched for a spacer which avoids wear debris due to methacrylate friction against bone, delivers a local antibiotic, is easily removed, and does not worsen bone damage. Since 1995, we have used a Charnley Kerboull type prosthesis as a spacer. The purpose of the present study was to 1) verify the absence of spacer-related complications, 2) assess outcome in terms of cure of infection and improved function.

Material and methods: We used 14 articulated spacers for two-phasee prosthesis replacement in nine men and five women, mean age 64 years. Erythrocyte sedimentation rate was 32 and C-reactive protein was 17. The mean Postel-Merle d’Aubigné (PMA) score was 3+5+2. All patients were reviewed at a minimum 37 months follow-up. Technique: The approach was generally a digastric trochanterotomy, associated with a more or less extensive femoral procedure (depending on the length of the plug to remove) to achieve removal of all implants and cement. A small-size polyethylene cup was inserted with cement delivering at least one antibiotic on a Surgicel bed to facilitate later extraction. A long small-diameter femoral stem was then inserted (bridging the femoral window) and blocked with cement, also on a Surgicel bed. Partial then total weight bearing was authorised between the phases.

Results: There were no dislocations. All patients achieved total weight bearing between the two phases. The same germ identified at the first operation was also identified at the second in two patients, requiring prolonged antibiotic therapy. There was one septic failure, in a different patient. The mean PMA score was 5.7+5.8+5.2.

Conclusion: This technique avoids methacrylate wear induced by classical spacers and does not modify polymorphonuclear chemotactism, facilitating the efficacy of medical treatment. Patient comfort is also improved between the two phases and muscle atrophy, which could compromise long-term function, is avoided.

Controversy exists with regard to the thickness of cement mantles that are necessary around the femoral components of cemented total hip arthroplasties. Conventional teaching, based on bench-top or computor models and theoretical analyses, as well as post-mortem & follow-up studies, suggests that the cement mantle should be complete and not less than 2–3mm in thickness. Mantles that are less than this are held to be at risk from mechanical failure in the long term; if they are incomplete, focal lysis may occur and progress to aseptic loosening.

However, long term experience with a number of French cemented femoral components suggests that these conventions may be erroneous. These French femoral components include the Charnley-Kerboull (stainless steel) and the Ceraver Osteal (Ti6Al4V) stems, in both of which the underlying design principle is that the stem should completely fill the femoral canal, the cement then being used purely to fill the gaps. Such a design philosophy implies that the cement mantles will be very thin, and since both of these stems are straight and the femoral medullary canal is not, the mantles may not only be thin, but also in places incomplete.

Conventional teaching would suggest that any stem utilising mantles of this type would fail from a combination of focal lysis and cement fracture. Yet the long term results of both of these stems have been outstandingly good, with extremely low levels of aseptic loosening and endosteal lysis, irrespective of the bearing combinations being used. Both these stems have a surface finish of Ra < 0.1 microns. A third French design, the Fare stem, manufactured from Ti6Al4V and based on the same principles, was associated with bad results when manufactured with a rough (> 1.5 microns) surface, and appreciably better results after the surface roughness was changed to < 0.1 microns.

These findings, that constitute the ‘French Paradox’, have profound implications for the mechanical behaviour of cement in the femur and for the mechanisms that underlie stem failure from loosening.

In early secondary arthritis due to femoral dysplasia, varus osteotomy achieves a control of arthritis for two decades in 80 % of cases : it is therefore a very reliable conservative treatment. Moreover, in carefully selected cases of severe arthritis in young active patients, a valgus osteotomy can achieve pain relief for a decade in 70 % of cases.

THE VARUS OSTEOTOMY is recommended when the arthritis is due to a coxa valga ≥ 140°. By reducing the inclination angle to 125° the abductors level of arm is optimized, and their contracture is decreased. Therefore, the osteotomy reduces the surface strains, but it does not improve the extent of articular surfaces.

A – INDICATIONS

1) Four factors are mandatory to achieve long term improvement:

The arthritis must be the consequence of the dysplasia, with degenerative changes localized at the supero lateral part of the head and of the acetabulum. This can be confirmed by isotope scanning. If the arthritic changes are not localised the desease is rather a primary arthritis, or an inflammatory or a metabolic disease, which are not an indication for a biomecanical treatment.

2) Therefore varus osteotomy is not recommended

in a non symptomatic dysplasia (as some of them may not lead to arthritis), or if the symptoms are those of a labrum syndrom, with suddent pain, instead of a progressive and mechanical arthritic pain.

3) The assosciated dysplasia have to be taken into consideration

If there is a femoral hyperanteversion there are two different conditions in the adult :

B – SURGICAL TECHNIC

The importance of the varisation depends on that of the coxa valga. The final inclinaison angle must be 125°, as the lever of arm of the abductors is impaired for a lower angle. Moreover there is a post operative limping due to the ajustement of the glutei length, the duration of which is function of the varisation (one year per 10°). To reduce this limping, only the necessary varisation has to be made.

C – RESULTS

There are less thant 5 % mechanical complications. An antalgic effect is obtained within some weeks. In 80 % of cases, painlessness and absence of radiological deterioration for two decades is achieved, a THR becoming necessary in the third decade. In 20 % of cases, only a temporary effect is obtained, leading to a THR after 5 to 10 years.

THE VALGUS OSTEOTOMY is at present used in only seldom cases of young patients with a severely damaged articulation, but who prefer an antalgic conservative surgery than a THR, because they wish to continue for a decade a strenuous activity not compatible with an arthroplasty. This can be made only when there are two large osteophytic drops of the acetabulum and of the femoral head, which can be put into contact by the valgisation, and facilitate healing of the superior lesions. In carefully selected cases, a relief of pain is achieved for a decade in 70 % of patients.

IN CONCLUSIONS

The femoral varus osteotomy remains one of the most reliable conservative operations in osteoarthritis due to DDH. However to achieve these good results, a clear understanding of the indications and biomechanical demands of this operation is required.

In seldom and selected cases of severe arthritis, a palliative valgus osteotomy can achieve a decade of pain relief.

For unstable fractures of the femoral shaft, the current interlocking nails are the most reliable fixation. However, these procedures require the use of an image amplifier for targeting the distal screws, and are expensive, ancillary instrumentation and an extensive stock of numerous nail sizes with various diameters, sides, and lengths is necessary.

We report a consecutive series of 60 unstable femoral fractures treated with the Endolock nail. This closed 11 mm diameter nail is introduced after little or no reaming. Distal fixation is achieved by means of a spur that unfolds from the nail and fixes into the posterior metaphysis. Radiological control during the procedure is recommended but not mandatory.

Fusion was achieved in all cases but three (5%). Two were aseptic in the same patient who presented two upper limb non-unions, and one with infection (little or no reaming was used in the nine open fractures). Eight moderate mal-unions were observed (angulation < 10°, external rotation < 20°, shortening < 20 mm) but did not require re-operation. All of these were the consequence of insufficient reduction of the fractures. No secondary displacement occurred between operation and fusion. No complications related to spur penetration or removal were observed.

The Endolock nail allows satisfactory interlocking without the mandatory use of an image amplifier, with little or no reaming, and at a low cost.