Introduction: There are a number of classification systems for inter trochanteric fractures of the proximal femur but none that have been universally accepted. For a classification to be successful, it should have excellent reliability and reproducibility among all reviewers in the interpretation of the radiographs. Although the Tronzo classification system is used for inter trochanteric fractures, its reliability had not been tested yet.

Aims: The purpose of this paper is to present the interobserver and intraobserver reliability of the Tronzo classification for intertrochanteric fractures of the femur.

Methods: The radiographs of 50 patients with inter trochanteric fractures were classified by seven observers according to Tronzo’s classification. Three observers were consultant orthopaedic surgeons with a minimum 12 years orthopaedic experience and four were orthopaedic residents. All observers worked independently. The observers repeated the measurements three weeks later without reference to the previous assessments. Intra- and inter-observer agreement was evaluated using the weighted kappa (k) coefficient of Cohen as calculated by the Stata computer package.

Results: For time1, the inter-observer is 0.19 (95% CI 0.05 to 0.43) and for time 2 it is 0.20 (95% CI 0.06 to 0.44): jointly the kappa estimate is 0.20 (95% CI 0.09 to 0.36).

For the intra-observer reliability, the kappa is sightly higher, as one would expect, although it is still only 0.41 (95% CI 0.25 to 0.55).

Overall, the inter-observer reliability is slight (and at best, fair) and the intra-observer reliability is moderate. For clinical use a kappa of 0.8 is strongly recommended and clearly this was not achieved.

Discussion: Tronzo’s classification is simple, easy to use and is predictive of the method of reduction unlike the AO/ASIF classification that is more complicated with several groups and subgroups. However there is poor interobsever reliability as shown in our study. This suggests that comparison of results between studies using the Tronzo classification is not reliable enough to be of use. It should be stressed that reliability studies are not a measure of the accuracy of the classification. There is no right or wrong response in grading each radiograph. The analysis purely measures the reproducibility of the response between several observers.

Intraobserver reliability was moderate in our series, which suggest that individuals could use the Tronzo classification to document their results over a period of time to monitor long-term outcomes and to compare treatment modalities in the same studies.

Purpose: The objective of this study was to observe the change in dislocation rate by introducing a capsular enhanced short external rotator repair during primary total hip arthroplasty.

Dislocation after primary total hip arthroplasty is a relatively common complication. The incidence is usually between 1% and 4%, although 0% to 10% has been reported in the literature. The posterior approach is by far the most popular by surgeons, but it reportedly has an increase risk of post-operative dislocation. The posterior approach causes disruption of the posterior capsule and the short external rotators. Studies have shown that repair of the posterior capsule and the short external rotators greatly reduce the dislocation rate.

Method: Review of the dislocation rate of THR’s by a single surgeon before and after the introduction of a capsular enhanced short external rotator repair (August 2002). It was a sequential cohort of 2213 Total Hip Replacements (THR), inserted over a period from January 1999 to June 2004. All cases were done by the senior author through a posterior approach using a Belfast custom stem, a 28mm head, and a cementless socket. We collected data on all dislocations which occurred on the hips inserted during this time period. We were therefore able to compare dislocation rates for THR’s done before and after the introduction of the soft tissue repair. The posterior capsule and short external rotators were reattached to the greater trochanter through drill holes using a number 5 Ethibond.

Results: This dislocation rate before the introduction of the new posterior soft tissue repair was 3.9% (58 out of 1501 THR’s). After the introduction of the repair the dislocation rate was 0.9% (6 out of 712 THR’s). 81% (47 of58) of dislocations before the change of practice were classed as early dislocations (with 3 months of surgery). 83% (5 of 6) were clearly dislocators after the new soft tissue repair. Considering only the early dislocations, the dislocation rate reduced from 3.1 to 0.7%.

Conclusion: Considering our reduction from 3.9% to0.9%, and results of previous studies, it is clear that the capsular enhanced and short external rotator repair is associated closely with a decreased dislocation rate. We feel other factors such as restoration of joint centre ensuring correct orientation of components are important in conjunction with the posterior soft tissue repair to keep dislocations to a minimum.

Dislocation is a recognised complication following the posterior approach in total hip arthroplasty. The senior surgeons involved in this study had routinely repaired the short external rotators and capsule by directly suturing ‘tendon to tendon’ and ‘capsule to capsule’ using No 1 Vicryl®. Over a two-year period this had no impact on the incidence of dislocation as compared to “no soft tissue repair” that had been done historically. In order to assess the effectiveness of ‘soft tissue to soft tissue’ repair fifteen patients were assessed using radiographic markers inserted during surgery. In 14 of the 15 patients the repair was found to have failed by the time of the post-operative x-ray which was taken on day 3 to 5. Since then we have changed the repair so that the capsule and rotators are reattached to bone with No 5 Ethibond® using drill holes in the trochanteric region. This modification was evaluated using the same method. Of 15 patients in the second type of repair only 2 showed a failure of repair on the post operative X-ray. This appears to be a more secure form of repair. The impact of this on the incidence of dislocation is being evaluated.

We performed a prospective clinical study in order to assess the effectiveness of repair of the short hip rotators, divided in the course of total hip replacement by the posterior approach, by the use of radio-opaque markers.

Fifteen patients, each with a diagnosis of osteoarthritis of the hip, were selected consecutively from a single surgeon’s operating list. Uncemented Duraloc® acetabular components and custom made cemented femoral components were implanted via the posterior approach in all patients.

Following implantation, the capsule and the short rotator tendons were sutured on to tendinous soft tissue around the greater trochanter using No 1 Vicryl. One radio-opaque marker clip was attached to the short rotators and capsule and a second marker was attached to the greater trochanter.

Standard antero-posterior pelvic X-rays were taken at three to five days post-operatively, and at three months following surgery. Significant separation of the radio-opaque markers in fourteen of the fifteen patients was demonstrated on the day three to five X-ray, indicating failure of the repair.

We conclude that this soft tissue repair is unsatisfactory. It may be of value to develop a more effective repair technique, with the overall aim of reducing total hip replacement dislocation, and as such we are currently investigating a soft tissue to bone repair.

In Musgrave Park Hospital, Belfast, younger patients requiring THR were treated by custom-made titanium alloy femoral prosthesis. The identifit hips, which were used initially, were intraoperatively customised by preparing a silicon mould of the endosteal cavity and immediate computer assisted fabrication. The Xpress hips used measurements from preoperative marker x-rays allowing creation of templates and subsequent computer analysis to mill a stem prior to surgery.

7 identifit and 51 Xpress primary uncemented custom THRs were inserted in 50 patients between May 92 and June 96. The average age for the indentifit cases was 47 years (range 24–72) and the Xpress cases 39 years (range 23–51). The Xpress cases were followed up to an average of 47 months (range 12–74 months) and identifit cases to an average of 59 months (range 14–77 months). The indications for arthroplasty were osteoarthrosis in 15 hips, CDH in 14, dysplasia in 11, AVN in 4, rheumatoid arthritis in 3 and other diagnosis in 11. Clinical assessments were made using the Oxford score and the Modified Harris Hip score. The postoperative radiographs were evaluated for subsidence of the prosthesis; and adaptive osseous changes like osteolysis, hypertrophic cortical remodelling, sclerotic radiolucent line formation around the prosthesis and formation of a bone pedestal below the tip of the prosthesis.

The average post-op Oxford hip score for those patients not revised was 32.5 /60 (range 12–51).

16 of the 51 Xpress hips underwent revision and 2 were awaiting revision, which is a failure rate of 35.3%. Of the identifit hips 1 out of the 7 was revised (14.3%). Overall 32.8% was the rate of failure. The average duration from primary operation to revision was 47 months for Xpress hips and 90 months for the identifit hips. Of the Xpress hips, revision was done for acetabular component in 1, femoral component in 4, both components in 1, acetabular liner + femoral head in 1 and acetabular liner + femoral component in 9. The 1 revision in the identifit hip was for recurrent dislocation.

The reasons for revision in the Xpress hips were dislocation in 2 cases, loose femoral component in 13 cases and infection in 1.

Average subsidence of the femoral component was 6mm (range 0–25.9) and this did not have significant correlation with predicting outcome. Pedestal formation (intramedullary formation of bone beneath the tip of the femoral stem) was seen in 87%, sclerotic rediolucent lines were seen in 64%, osteolysis was found in 31% and hypertrophic cortical remodelling was seen in 31%. These also did not reach significance in predicting outcome.

Thus even though the idea of an uncemented custom THR is attractive, especially in the younger age group, the failure rate was found to be unacceptably high. On the basis of these data we have discontinued the use of this custom made non-porous uncemented femoral prosthesis.