Aims

The duration of systemic antibiotic treatment following first-stage revision surgery for periprosthetic joint infection (PJI) after total hip arthroplasty (THA) is contentious. Our philosophy is to perform an aggressive debridement, and to use a high local concentration of targeted antibiotics in cement beads and systemic prophylactic antibiotics alone. The aim of this study was to assess the success of this philosophy in the management of PJI of the hip using our two-stage protocol.

Aim

The duration of systemic antibiotic therapy following first-stage surgery is contentious. Our Institution's philosophy is to perform an aggressive debridement, use high concentration targeted antibiotics through cement beads and systemic prophylactic antibiotics alone. In the presence of significant soft tissue infection or microbiological diagnostic uncertainty; systemic antibiotics may be prescribed for 5 days whilst awaiting tissue culture results. The aim of this study was to assess the success of our philosophy in the management of PJI of the hip using our two-stage protocol.

The duration of systemic antibiotics following first-stage surgery is contentious. Our Institution's philosophy is to perform an aggressive debridement, high concentration of targeted antibiotics through cement beads and systemic prophylactic antibiotics alone. In the presence of significant soft tissue infection or microbiological diagnostic uncertainty; systemic antibiotics may be prescribed for 5 days whilst awaiting tissue culture results. The aim of this study was to assess the success of our philosophy for two-stage hip revision.

A retrospective review of our Institution's prospective database was performed to identify all intended two-stage hip revision procedures for PJI. All patients had a confirmed PJI as per MSIS 2013 criteria, minimum 5-years follow up and outcomes according to the MSIS working group outcome-reporting tool; then grouped into “successful” or “unsuccessful” (suppressive antibiotics, further revision for infection, death within 1 year).

383 intended two-stage hip revisions were identified; of which 299 met our inclusion criteria, in 289 patients (6 repeat ipsilateral two-stage, 4 bilateral two-stage). Median follow up was 10.7 years (IQR 6.3 – 15.0). 258 (86%) patients proceeded to 2^nd stage surgery. 91% success rate was observed for those patients who underwent reimplantation, although dropping to 86% when including the patients who did not proceed to second stage. The median duration of post-operative systemic antibiotics was 5 days (IQR 5–9). No significant difference was observed in patients who received either; < / = 48 hours (86%; n=70) compared to > 48 hours antibiotics (86%; n=229; p=0.96) or </= 5 days of antibiotics (88%; n=202) compared to > 5 days antibiotics (82%; p=0.38). A significant majority had gram-positive (88%) infection with 30% being polymicrobial. Greater success rates were observed with two-stage exchange or gram-positive PJI (86%); than for gram-negative PJI (81%) and polymicrobial infection (74%) (p=0.36). Fungal PJI was observed to have a significantly reduced rate of success (n=3; 33%; p=0.03).

Aggressive surgical debridement with high concentration, targeted local antibiotic delivery at time of first stage to manage PJI of the hip provides a high rate of success, responsible antibiotic stewardship and reduced hospital costs.

The management of periprosthetic joint infection is challenging and the duration of systemic antibiotic therapy whether it be during the interval phase or after reimplantation of a new prosthesis is controversial. We report our experience of managing chronic periprosthetic infection of the hip by the two stage exchange procedure.

Patients who were scheduled to undergo a two stage revision for chronic periprosthetic infection of the hip were identified from our prospective database.

Of 425 patients with microbiologically proven periprosthetic infection, 369 (87%) underwent a two stage procedure, leaving 56 patients who did not proceed to reimplantation. 41 of these were clinically infection free but for personal or medical reasons did not proceed. The remaining 15 had persistent infection. The mean age at the time of the first stage was 68 years (26 – 92 yrs). 256 (61%) patients were alive for review. The mean time between stages was 6.3 months with a mean follow up after the second stage was 65 months (range 5 to 276 months).

The success rate of a single 1^st stage debridement, confirmed by negative cultures at the time of second stage reimplantation was 94%. 19 patients underwent a repeat 1^st stage debridement and were classed as failures of the 1^st stage. At the time of final review, 340 (92%) patients were deemed infection free out of those who had completed a 2 stage exchange.

The duration of systemic antibiotic treatment after both the 1^st and 2^nd stages was divided into <48 hrs and >48 hours. There was no significant difference in the success of the 1^st stage procedure in patients who received < 48 hours (48% of the patients) as opposed to > 48 hours (p = 0.98, Chi Squared Test, Relative Risk 1.009). Similarly there was no difference in the overall success of the two stage procedure irrespective of the duration of antibiotic therapy with 76% of patients receiving <48hrs of antibiotics after the second stage.

Aggressive surgical debridement together with targeted local and short term systemic antibiotic therapy should be the mainstay of treatment in two stage revision surgery.

Introduction

A recent paper suggested implanting an uncemented acetabular shell which is 6mm or greater than the native femoral head in total hip arthroplasty (THA) significantly increased the risk of postoperative pain. We retrospectively analyzed 265 Delta ceramic-on-ceramic (DCoC) THA comparing the native femoral head size to the implanted shell and reviewing if the patient suffered with post-operative pain (POP).

AIM

When a hip is replaced using a posterior surgical approach, some of the external rotator muscles are divided. The aim of this study was to assess if this surgery has a long term affect on hip rotation during activities of daily living.

Introduction: The aim of this study was to compare hip movement between normal subjects and patients with a large Metal on Metal hip replacement, undertaking the task of retrieving an object from the floor.

Methods: An electromagnetic tracker was used to measure movement as subjects retrieved an object with flexed hips and straight knees. Measurements were taken from a control group of 10 subjects with bilaterally normal hips, and 10 subjects with unilateral hip replacement. Sensors were attached over the iliac crest and the mid-shaft of the lateral thigh. Data was collected as each subject repeated the movement 3 times. The tracker recorded data at 10 hertz, with an accuracy of 0.15 degree.

Results: For the normal group the mean hip flexion was 90.8 degrees (SD 20.1). For the arthroplasty group the mean flexion on the normal and operated sides were 74.0 (SD 21) and 72.7 degrees (SD 21) respectively. This was not significant (P= 0.83). However there was a significant difference in hip movement between the operated hips and those in the normal control group (P= 0.03).

For the bilaterally normal group the mean hip rotation was 2.9 degrees internal (SD 11.8). For the arthroplasty group the mean rotation on the normal and operated sides were 9.4 degrees external (SD 9.5) and 6.9 degrees internal (SD 13.9) respectively. In this group there was a significant difference between the normal and operated side (P= 0.02).

Discussion: This study has shown that patients with a unilateral hip replacement have no significant flexion difference between hips, when retrieving an object from the floor. However there was a significant difference compared to a control group with normal hips. A significant difference was also observed when comparing the rotation of an operated hip joint to the contra-lateral normal hip in the same individual.

Introduction: Patients undergoing total hip arthroplasty are advised to minimise their hip flexion in the early postoperative phase, to reduce the risk of dislocation. One activity that requires hip flexion is picking an object up from the floor. The aim of this study was to investigate the amount of hip flexion required to perform this task, and to see if there is a difference between patients with small and large bearing total hip replacements.

Methods: Nineteen unilateral total hip replacement patients were recruited into the study. Nine had a small bearing (metal on plastic) implant and ten had a large bearing (metal on metal) implant. Each patient had a contra-lateral normal native hip, which provided a control for bilateral comparison.

An electromagnetic tracking system was used to measure the flexion in the operated and normal hip of each patient. Tracker sensors were placed on the iliac crest and the mid-lateral thigh. The patients were then asked to flex forward from a standing position to pick an object up off the floor. This movement was repeated 3 times. Flexion data was collected at 10Hz which was accurate to 0.15 degrees. Spinal flexion was not recorded during the task.

Patients were also asked to complete the Harris and Oxford Hip Score questionnaires to obtain qualitative data regarding their hip replacement.

Results: The mean peak flexion angles (degrees) for each group are given below:

Small bearing group:

Operated side: Peak flexion = 79.3

Comparing the small bearing group with the large bearing group, the peak difference was 6.6. This difference was non-significant with P = 0.43.

All patients reported good – excellent functional results when completing the Harris and Oxford Hip Scores.

Discussion: The investigation showed that picking an object up from the floor requires a peak hip flexion of approximately 80 degrees. This investigation found no significant difference between the normal and operated sides. This would suggest that a Total Hip Replacement restores the “normal” range of motion in a hip joint. Furthermore, there was no significant difference between the small and large bearing hip implants.

Introduction: There is a paucity in the literature regarding the long term outcome of children with septic hips. Often, there is a delay in diagnosis which may lead to complications such as growth arrest, deformity and leg length discrepancy. We investigated the outcome of these patients and report the observed complications.

Methods: We performed a retrospective review of all children who underwent arthrotomy and washout for septic arthritis of the hip over a ten year period. Patients were identified from hospital databases and the coding department. Medical records were reviewed and data including demographics, method of presentation, laboratory investigations and outcome were recorded.

Results: We analysed the records of 70 patients who underwent formal arthrotomy and washout of their septic hip. Two patients had bilateral washouts (n = 72 hips). There were 36 (51%) female patients. 24 patients were under 1 year of age at presentation, with 11 of these in the neonatal period.

Temperature data was available for 48 patients, with a mean of 38.2 degrees Celsius at presentation. The mean ESR was 55.8. 28 patients (40%) grew an organism on culture of the hip fluid. The most common organism was Staphylococcus Aureus (64% of positive cultures).

66% (n=16) of patients in the < 1 year old group developed complications relating to growth arrest and leg length discrepancy. Seven of these patients (43%) underwent further surgery to correct deformity at a later date. In contrast, only 4.3% of patients in the > 1 year old group developed complications. The mean delay to surgery in patients who developed complications was 6.3 days with a mean delay to surgery of 3.1 days in patients who did not develop complications (p = 0.03, student’s T-Test).

Discussion: Paediatric Septic Arthritis remains a complex issue for both the patient and the surgeon. We have demonstrated that an increased delay in patients undergoing washout can lead to increased complications although this predominantly affects patients under 1 year of age. This can be explained by the lack of clinical signs in a < 1 year old child. Clinicians should have a high index of suspicion of septic arthritis in patients with features of sepsis with an unknown cause.

Introduction: Hip replacement patients are prone to dislocations during extreme hip movement in the early post operative period. An activity of daily living that puts them at risk of dislocation is picking an object off the floor. The aim of this study was to assess the movement of the hip using different techniques to pick an object of the floor.

Methods: An electromagnetic tracking system was used to assess hip movements for four different techniques in picking an object from the floor. These were -

Flexing forward to pick an object up between the feet.

Measurements were taken from 40 hips in 20 normal subjects aged 21 to 61. Sensors were attached over the iliac crest and the mid-shaft of the lateral thigh. Data was then collected from the magnetic tracker as each technique was repeated 3 times. The system recorded hip flexion and rotation data at 10 hertz, with an accuracy better than 1 degree. Data was then analysed and the mean readings for each technique were compared.

Results: For each of the four techniques listed above the respective mean (SD) results were:

Flexion: 81.4 (27.5), 83.3 (27.6), 93.3 (28.7) and 33.5 (17.6) degrees.

The most significant movements for each technique were flexion and external rotation.

The movements with the least and most flexion were kneeling (33.5 deg) and squatting (93.3 deg). They were significantly different with a paired t-test p< < 0.001.

The movement with the least and most external rotation were kneeling (7.5 deg) and side pick up (22.7 deg). They were significantly different with a paired t-test, p< < 0.001.

Conclusion: This study has found that the most effective technique to pick up an object from the floor is kneeling as this has the least amount of flexion and external rotation. We conclude that this is the safest technique in carrying out this activity in the early post operative stage for patients who have undergone a total hip replacement.

Introduction: Activities that require extreme hip movement can dislocate hip implants in the early post operative phase. The aim of this study was to assess the movement of the hip using four different techniques to retrieve an object from the floor.

Methods: An electromagnetic tracker was used to measure hip movement during these retrieval techniques:-

Flexing forward to pick up an object between the feet

Measurements were taken from 50 hips in 25 normal subjects aged 21 to 61. Sensors were attached over the iliac crest and the mid-shaft of the lateral thigh. Data was collected as each technique was repeated 3 times. The tracker recorded hip flexion and rotation data at 10 hertz, with an accuracy of 0.15 degree.

Results: For each of the four techniques the respective mean (SD) movements were:-

Flexion: 75.8(28.6), 79.2(27.2), 87.5(29.7) and 30.4(17.3).

Kneeling had significantly less flexion and external rotation than all the other techniques (paired t-test, P< < 0.001).

Discussion: Flexion and external rotation were the most significant movements for each technique. The movements with the least and most flexion were kneeling (30.40) and squatting (87.50). The movement with the least and most external rotation were kneeling (7.30) and side pick up (20.10).

Kneeling has the least amount of movement, therefore, it minimises the risk of dislocation when retrieving an object from the floor.

Introduction: Intra-articular steroid injection has long been used to treat osteoarthritis of the knee and hip by orthopaedic surgeons, rheumatologists and general practitioners. Recent literature has shown conflicting results with regard to its safety. We aimed to investigate whether a relationship exists between preoperative intra-articular steroid injection and postoperative infection in total knee arthroplasty (TKA).

Patients and Methods: We reviewed the records of all patients having TKA between April 2005 and April 2007 in University Hospital Aintree, Liverpool. The operations were carried out by 6 consultants. Exclusion criteria for analysis were: previous knee infection, revision knee surgery, fracture around the knee, skin disorders, diabetes, blood transfusion, rheumatoid arthritis and immunosuppressive medication. Eligible patients were divided into two groups: group I had received intra-articular steroid injection (each subject receiving 1–3 (mean 1.6) injections between 1–12 (mean 5) months before TKA); group II had received no injection. Mean follow-up was 17 months.

Results: 425 patients had TKA, of which 361 met our criteria. 121 patients in group I and 240 patients in group II. No-one in group I developed acute infection. In group II, 7 patients developed acute infection (5 superficial and 2 deep) between 1 and 6 weeks (mean 3.7 weeks) post-operatively. There were no late infections. The difference in infection rate between groups I and II was not statistically significant (P=0.1, Fisher’s exact test).

Conclusion: We found no evidence that intra-articular steroid injection prior to TKA increased the incidence of postoperative infection.

Introduction: The subtrochanteric area of the femur is subject to large tensile and compressive forces. The rate of nonunion following operative fixation of such fractures is about 7–20%. Revision surgery to obtain union is difficult because of the small size of the proximal fragment, muscle forces acting in 2 planes, and bone loss.

We present the results of a series of 9 consecutive patients with subtrochanteric non-unions treated by double plates.

Methods: Retrospective analysis of 9 consecutive subtrochanteric nonunions treated with double plates and additional osteoinduction (bone graft, or BG+BMP-7).

Results: There were 5 male and 4 female patients, with ages from 50–82 years (mean 65). All were treated in a single-stage procedure by implant removal, a lateral plate and a separate anterior plate. One patient had had a previous unsuccessful revision procedure with an intra-medullary device.

One patient with liver cirrhosis died 5 days postoperatively. Two patients are currently 8 weeks post surgery. All the others healed in a mean of 5.1 months (range 4–6 months).

Two patients underwent distal femoral lengthening to compensate for bone loss.

Discussion: The high muscle forces around the proximal femur require a sound mechanical environment for bone healing to occur. This is particularly marked in nonunions. The small size of the proximal fragment can result in suboptimal fixation. The addition of the anterior plate provides better fixation and also neutralizes the sagittal forces.

We believe that double plating neutralizes all the forces around the proximal femur, providing the best mechanical environment. Given the limits of the small numbers and the retrospective nature of the study, we believe that this method of treatment offers a sound surgical strategy, reflected by our success rate.