Introduction

Vancomycin is a commonly used antibiotic for prophylaxis in total joint replacement surgery. Several studies have reported superior local tissue concentration of vancomycin using intraosseous (IO) infusion compared with standard intravenous (IV) administration in total knee arthroplasty (TKA). We reviewed patients undergoing primary TKA who received IO vancomycin to a group receiving IV vancomycin.

Objectives

The aim of this study was to investigate the biomechanical effect of the anterolateral ligament (ALL), anterior cruciate ligament (ACL), or both ALL and ACL on kinematics under dynamic loading conditions using dynamic simulation subject-specific knee models.

Objectives

Unicompartmental knee arthroplasty (UKA) is an alternative to total knee arthroplasty for patients who require treatment of single-compartment osteoarthritis, especially for young patients. To satisfy this requirement, new patient-specific prosthetic designs have been introduced. The patient-specific UKA is designed on the basis of data from preoperative medical images. In general, knee implant design with increased conformity has been developed to provide lower contact stress and reduced wear on the tibial insert compared with flat knee designs. The different tibiofemoral conformity may provide designers the opportunity to address both wear and kinematic design goals simultaneously. The aim of this study was to evaluate wear prediction with respect to tibiofemoral conformity design in patient-specific UKA under gait loading conditions by using a previously validated computational wear method.

Introduction

Hip abductor tendon tears have been referred to as “rotator cuff tears of the hip,” and are a recognized etiology for persistent, often progressive, lateral hip pain, weakness, and limp. Multiple repair techniques and salvage procedures for abductor tendon tears have been reported in the literature; however, re-tear remains a frequent complication following surgical repair. This study compares the short-term outcomes of open abductor tendon repairs with decortication and suture fixation (DSF) compared to a modified technique repair into a bone trough (BT), to determine best surgical results for large abductor tendon avulsions. Additionally, surgical treatment of small tears versus large tears was examined.

Introduction

Reinforcement ring with allograft bone is commonly used for acetabular reconstruction of bone defects because it can achieve stable initial fixation of the prosthesis. It is not clear whether the allograft bone can function as a viable host bone and provide long-standing structural support. The purpose of this study was to assess to long-term survival of the reinforcement rings and allograft bone incorporation after acetabular revisions.

Osteonecrosis of the femoral head (ONFH) is a painful and disabling condition, which most commonly involves the hips of young patients. But despite of the high incidence, treatment is still has not been definitely identified. We performed a modified muscle pedicle bone graft (MPBG) technique using anterior one-third of gluteus medius (GM) attached to the greater trochanter (GT) in ONFH. The purpose of this study was to evaluate the effectiveness of our technique on ONFH in ARCO stage II and III patients.

Between June 2007 and March 2015, 24 hips were treated by our technique, who were able to follow up at least 2 years. The group was consisted of 15 men and 8 women, mean age of 36 years at the time of surgery. Mean follow-up was 5 years.

Twenty of 24 hips hips had no progression of necrotic lesions. The postoperative scintigrams showed increased blood flow in the 3 month follow up evaluation. But 4 hips underwent THA at the mean follow-up of 6 years after the surgery, and considered as “failure”. Excluding the 4 failed cases, the mean Harris hip score was improved from 54 points to 85 points at the last follow up.

Through our new technique, we showed 83% of survival rate by average of 5 year follow up. And compared to other reports, our technique showed relatively good survival rate and clinical outcomes. Therefore, we suggest this modified technique as one of promising treatment of choices for young patients with ARCO stage II or III ONFH.

Aim

Identification of the causal pathogen is crucial in the management of periprosthetic joint infection (PJI) of the hip. Unfortunately, it was often difficult and negative culture could be a common findings. This situation made the treatment of PJI of the hip became more challenging. The negative culture finding resulted in a doubtful diagnosis of infection, and poses difficulty in choosing the appropriate antibiotics. Here we compared the treatment outcome of two-stage revision arthroplasty for culture-negative versus culture-positive PJI of the hip.

Introduction

Septic knee arthritis with severe osteoarthritis (OA) presents challenging clinical situations because of unexpected and long time for treatment and less satisfactory clinical outcomes. Septic arthritis with damage to articular cartilage developed osteomyelitis (OM) frequently. Although arthroscopic debridement was the common treatment of septic arthritis, there was some limitation on the management of infected bone structures and then open arthrotomy should be reserved. In the patients of OM located only periarticular areas, the author used the PROSTALAC system for infected total knee arthroplasty (TKA) and achieved good results.

Background

Need for hip or knee arthroplasty is rapidly increasing in aging society nowadays. Accordingly, orthopedic surgeries for patients with various diseases of high mortality rates are becoming indispensable. Patients with liver cirrhosis undergoing major orthopedic surgery like joint arthroplasty are at risk of many complications including infection and excessive bleeding. In this study, we want to present helpful measures to prevent expected complications that can occur with hip or knee arthroplasty performed on patients with liver cirrhosis through comparative analysis on the prognosis of relevant patients studied at our hospitals.

Introduction

An equal knee joint height during flexion and extension is of critical importance in optimizing soft-tissue balancing following total knee arthroplasty (TKA). However, there is a paucity of data regarding the in-vivo knee joint height behavior. This study evaluated in-vivo heights and anterior-posterior (AP) translations of the medial and lateral femoral condyles before and after a cruciate-retaining (CR)-TKA using two flexion axes: surgical transepicondylar axis (sTEA) and geometric center axis (GCA).

Background

The patients with high hip dislocation due to the sequelae of septic hip or neglected Developmental Dysplasia of the Hip (DDH) show severely impaired gait pattern. Total hip arthroplasty (THA) for these patients are expected to restore gait pattern by establishing better joint stability and biomechanics. To our knowledge, no study have investigated about objective change in gait parameters after total hip arthroplasty (THA) for these patients. So, we are to prospectively evaluate change in gait patterns after THA.

Purpose

There are still some controversies over the routine use of negative suction drainage after primary total hip arthroplasty (THA). In this study we are to know the benefits of new suction drainage management strategy after primary THA.

Introduction

Total hip arthroplasty (THA) is the most common surgery performed for complications of bipolar arthroplasty. The present study evaluated the functional results and complications associated with this surgery.

Purpose

The purpose of this study is to evaluate the midterm results of cementless revision total hip arthroplasty (THA) using Wagner Cone Prosthesis.

Purpose:

The purpose of this study was to evaluate the results of two stage reconstruction for infected arthroplasty of hip joint and to know the risk factor for failures.

Background

One of advantages of single-radius femoral design was to offer better ligament stability based on a maintained isometry of extensor muslce during the whole range of motion. The purpose of this study was to compare intraoperative varus-valgus laxities from 0° to 90° of flexion in patients that received TKA using either a single-radius femoral design or multiradius femoral design.

Purpose

We analyzed a consecutive series of 36 total hip arthroplasties using cementless conical stem with a shortening osteotomy combined with greater trochanter transfer in cases with a high dislocated hip.

Purpose

Bilateral simultaneous and staged total hip arthroplasty has been issues in terms of safety and costs with development of surgical technique, postoperative medical care. The purpose of this prospective study is to compare the outcomes of simultaneous and staged bilateral operations, in terms of outcome, safety, and socioeconomic-effectiveness.

Purpose

The purpose of this study was to evaluate the complications related to the prosthesis design in patients managed with cemented total knee arthroplasty (TKA) with the anterior-posterior glide (APG) mobile bearing prosthesis.

Introduction

The purpose of this study was to evaluate the functional and radiographical results in patients who underwent a modified minimally invasive two-incision total hip arthroplasty using large-diameter ceramic-on-ceramic articulations for osteonecrosis of the femoral head.

We performed this study to evaluate the clinical and radiological results of metal on metal articulation change for the treatment of ceramic liner or head fractures in total hip arthroplasty (THA).

We retrospectively reviewed 8 patients with revision THA using liner cementation (metal on metal) due to ceramic fracture (liner fracture; 5 cases, head fracture; 3 cases).

They were followed up for an average of 30 months (range 12 to 68 months). At the surgery, we removed ceramic liner and head, the joint cavity was irrigated with saline to remove remnants of ceramic particles. After that, the inner surface of the metal shell was roughened with a high-speed diamond burr to improve the fixation strength of the liner.

Metal inlay polyethylene (Metasul^®, Centerpulse Orthopedics, Austin, TX) liner was used and the back surface of the liner was routinely down sized and roughened like spider web with an electrical burr to ensure stable fixation with bone cement.

We evaluated clinical result using Harris Hip Score (HSS) and the Western Ontario and McMaster Universities Osteoarthritis index (WOMAC) score and radiological evaluation was done using the mothod of DeLee and Charnley for the acetabular osteolysis and method of Gruen et al. for the femoral osteolysis.

The mean Harris hip scores improved from 65.3 pre-operatively to 93.8 at the final follow-up. There were no changes in cup position, no progression of osteolytic lesion around the femoral and acetabular components and no measurable wear of metal on metal bearing articulation at the last follow-up radiographs. There was one case of recurrent dislocation after surgery and the patient treated with greater trochanter distal advancement.

This study showed that for the treatment of ceramic liner or head fractures, after thorough removal of ceramic particles, cementation into a metal shell and changing the articulation to metal-on-metal provided good clinical and radiological results.

The purpose of this prospective study was to investigate the necessity of gender-specific design in total knee arthroplasty (TKA) for Korean women.

One hundred and seventeen women (151 knees) who underwent primary TKA by one surgeon with Nexgen^® LPS (Zimmer, Warsaw, IN) were evaluated. The mean age was 70 (range 52–80) years. The size of the implant was determined by considering anteroposterior (AP) dimension and the amount of posterior condylar resection. Size C was used in 72 knees, size D in 57 and size E in 22. We measured the mediolateral (ML) widths of distal femur at four points (anterior, distal anterior, distal posterior, posterior) intraoperatively after bone cutting, and compared them with the ML widths of the corresponding femoral implants. The ML/AP ratio was calculated in each size group.

The mean ML widths of the distal femur checked at all four points were larger than those of the implants. The ML/AP ratio of the distal femur decreased as the size increased from C to E, especially that of the anterior point. Overhanging occurred in 7 cases (4.6%, size C -2 cases, size D -2 cases, E -3 cases) : Nexgen^® LPS implant was used in 5 cases because there was only minimal antero-lateral overhanging, resulting in no postoperative problem such as pain or limited motion. Gender-specific design was used in only 2 cases (1.3%, size D -1 case, size E -1 case) with trochlear dysplasia due to general overhanging.

In conclusion, gender-specific design of Nexgen^® TKA was rarely necessary in 117 Korean women(151 knees); overhanging occurred in 7 knees (6 women) and gender-specific design was used in only two knees (1.3%) with trochlear dysplasia. Further research is obviously mandatory to assess the necessity of gender-specific design.

The aim of the present study was to report the midterm follow up results of second generation metal-on-metal cementless total hip arthroplasties in patients younger than 50 years.

From December 1997 and January 2003, 91 metal-on-metal cementless primary total arthroplasties in 77 patients (who were younger than 50 years) were performed in our institution. Among them 72 hips in 63 patients could be followed more than 5 years. There were 18 women (22 hips) and 44 men (50 hips) with a mean age at surgery of 39 years (range 22 to 49 years) and a mean follow up of 7 years (range 5 to 10 years).

The most common cause of total hip replacement were avascular necrosis of femoral head (37 hips in 28 patients, 51%) and second one was osteoarthritis (13 hips in 13 patients, 18%). We used Fitmore (Zimmer, Winterthur, Switzerland) cup in all cases and used 28mm Metasul femoral head. About the femoral stem, CLS (Protek AG/Zimmer, Bern, Switzerland) stems were used in 48 hips and Cone prosthesis^® (Protek AG, Berne, Switzerland) were used in 24 hips.

We evaluated clinical result using Harris hip score (HSS) and the Western Ontario and McMaster Universities Osteoarthritis index (WOMAC) score and radiological evaluation was done using the method of DeLee and Charnley for the acetabular osteolysis and method of Gruen et al. for the femoral osteolysis.

The mean HSS improved from 58.9 (range 35 to 69) preoperatively to 92.2 (range 82 to 100) postoperatively. The mean WOMAC score improved from 72.2 (range 63 to 94) preoperatively to 29.2 (range 17 to 51) postoperatively. In radiological evaluation, all femoral and acetabular component were well fixed without loosening or subsidence. But osteolysis was observed in 10 (14%) of total 72 hips (Acetabular osteolysis in 5 cases-Zone 2; 2, Zone 3; 3, Femoral osteolysis in 6 cases-Zone 1; 6, Zone 7; 1).

About the major complications, there were immediate postoperative deep infection 1 case, delayed infection 1 case and recurrent dislocation 1 case. There was no revision case due to aseptic loosening.

The treatment of second generation metal-on-metal cementless total hip arthroplasties in patients younger than 50 years showed favorable midterm results.

The purpose of this study is to identify clinical and radiographic results of 78 uncemented total hip arthroplasties using Metasul^® metal on metal bearings with Wagner standard cup and proximal hydroxyapatite coated CLS stem.

Mean age was 39 years and average follow-up period was 11.7 years. Mean Harris hip score had improved from 51.4 points preoperatively to 95.2 points finally. There were 2 hips with progressive osteolysis around the acetabular cup. Of them, one hip was revised due to loosening of the cup, and the other was observed because of patient’s refusal to revise. In histopathologic findings on osteolytic area, a lot of macrophage phagocytizing metal debris and perivascular lymphocyte infiltration were found. Immunohistochemical analysis suggested delayed metal hypersensitivity. Serum cobalt levels in hips with osteolysis were not higher than those in hips without osteolysis.

Early osteolysis with sudden onset of groin pain in few hips remains a concern.

The two-incision technique uses strategically located incisions to insert the prosthesis components in to specific intermuscular or internervous planes in an effort to minimize damage to these tissues. Even though there are many reports about safety and benefits of bilateral simultaneous total hip arthroplasty (THA), none of them has reported about either one-incision or two-incision bilateral simultaneous minimally invasive (MI) THA. This study aimed to assess the feasibility of bilateral simultaneous MI two-incision THA in terms of clinical, radiological and functional outcomes.

Sixty two patients, in the age of 24 to 69 years were operated for bilateral simultaneous THA using modified two-incision technique and followed for average 41 months. In the technique of two-incision THA described by Mears, they used modification of Smith Peterson approach for insertion of acetabular component and femoral component is inserted through a small incision situated between greater trochanter and iliac crest, centered directly in line with the femoral shaft. We modified this technique and used part of Watson Jones approach for insertion of acetabular component with patient in lateral position. The posterior incision for insertion of femoral component is through intermuscular interval between gluteus medius and piriformis.

The average Harris Hip score improved from 41.8 (range 10 to 59) preoperatively to 95.3 (range 73 to 100) postoperatively (P < 0.05). WOMAC score improved from median of 66.2 (range 31 to 96) preoperatively to 5.0 (range 0 to 19) postoperatively (P < 0.05). Forty-nine (79.03%) patients were pain-free at the time of first follow up (6 weeks after surgery) and remained pain-free till the last follow up, while remaining 13 (20.97%) had only slight pain. Out of those 13, 3 patients complained of occasional mild pain at last follow up. Fifty (80.64%) patients were walking without limp, while remaining 12 (19.35%) had only slight limp at 6 months. Out of those 12, 2 patients had persistent limp at final follow up. Fifty-eight (93.53%) patients were walking without support, 56 (90.32%) were able to walk unlimited distance and 55 (88.70%) were able to climb stairs without using a railing. Walking with walker was started on average 3.7 days (range 1 to14 days) and walking with crutches was started on average 10.3 days (range 1 to 49 days) postoperatively. Patients were able to walk without support on an average 48 days (range 14 to 120 days) and use stairs without support and without any discomfort on an average of 50 days (range 5 to 150 days). The average lateral opening angle of acetabulum was 40 ° and anteversion was 12 °. All femoral components were implanted in neutral to 5 ° valgus position. None of the femoral component showed subsidence of more than 3 mm. The filling of the femoral canal by the prosthesis was excellent in all cases. Post-operative periprosthetic fracture occurred in 2 patients and delayed infection occurred in 1 patient.

In conclusion, bilateral simultaneous two-incision minimally invasive THA gives satisfactory clinical and radiological results in comparison with conventional THA. It is safe in experienced hands, without any additional risk of complications. It provides excellent functional outcome and patient satisfaction.

The purpose of this study was to evaluate the effect of decreasing tibial slope on extention gap during posterior stabilized total knee arthroplasty. 110 posterior stabilized total knee arthroplasties were studied for 2 groups;

having flexion contractures(n=35),

In each group, we measured the decrease of tibial slope and frequency of additional distal femoral resecions that were done due to insufficient extension gap in comparison with flexion gap during posterior stabilized total knee arthroplasty. We also compared frequencies of additional distal femoral resections between 2 parts having more and less slope decrease in each groups.

In each group, tibial slope decrease were 8.7 degrees, 7.4 degrees(p=0.145) and frequencies of additional resection were 51.4%, 24%(p=0.005) in average. In 2 parts having more and less slope decrease in each group, frequencies of additional resection were 44.4% vs 58.8%(p=0.505), 13.2% vs 35.1%(p=0.032). Results suggested that more decrease of tibial slope reduced frequency of additional distal femoral resection during posterior stabilized total knee arthroplasty in group having no flexion contracture.

Decreasing tibial slope can be considered as a factor influencing on extension gap during posterior stabilized total knee arthroplasty. The estimation of predictable tibia slope decrease through preoperative radiologic findings can be beneficial in performing succeful posterior stabilized total knee arthroplasty.

A consecutive series of patients who underwent 113 total hip arthroplasty (THA) with minimally invasive surgery (MIS) (63 one-, 50 two-incision cases) were studied. One-incision THA was performed with a posterolateral approach. For the two-incision, the first incision for cup insertion was made over the anterolateral side of the hip and intermuscular dissection was performed between the gluteus medius and the tensor fascia lata. The second incision for stem insertion was made on the posterolateral side along the fiber of the gluteus maximus and intermuscular dissection was made between the gluteus medius and the piriformis.

The average length of the skin incision and standard deviation (SD) in the one- and two-incision group was 7.5 ± 0.54 cm and 12.1 ± 0.93 cm (p < 0.001). Average surgical time for the two groups (and SD) was 52 ± 8.5 minutes and 70 ± 10.2 minutes (p = 0.042) in the one and two incision groups respectively. Fluoroscopy was used in the two-incision group for an average 6.0 ± 5.3 seconds. In the one-incision group, the average time was 1.3 ± 2.1 seconds.

The patients in the one-incision group could walk on crutches at postoperative 3.7 days on average, and in the two-incision group at 1.6 days on average (p = 0.000). In the one-incision group, patients used crutches for 6 weeks on average, and in the two-incision group, patients used crutches for 3 weeks on average (p = 0.042).

Complications that developed within 1 month of surgery in the one-incision group were: 1 case of DVT, 1 case of intra-operative fracture and 1 case of dislocation; for the two incision group there were: 1 case of DVT, 1 case of intra-operative fracture and 1 case of femoral nerve entrapment.

Before surgery, the HHS for the one-incision group was 49.8 points, and for the two-incision group it was 49.6 points (p > 0.05). At the time of the follow up review conducted postoperatively 1 year, the average HHS was not significantly different (p > 0.05). However, the average function score in HSS for the two-incision group was superior to that of the one-incision group (p = 0.045). Preoperative WOMAC scores were not different for the two groups (68.7 in one-incision group and 70.9 in two-incision group, respectively, p > 0.05). However, the average WOMAC score for the two-incision group was better, especially for the function score (p = 0.001). The other hip functions, common in oriental persons, were also better in the two-incision group compared to the one-incision group.

On the radiographs, the location of the femoral prosthesis inserted in the medullary cavity was usually central in both groups; only 4 cases showed varus in the one-incision group and 2 cases in the two-incision group. The opening angle of the acetabular component was 38.1° in the one-incision group and 39.2° in the two-incision group (p > 0.05). The anteversion of the acetabular component was 21.0° in the one-incision group and 22.2° in two-incision group (p > 0.05).

As compared with one-incision MIS-THA, two-incision MIS-THA, although it is a more difficult procedure, produces superior results, recovery was faster and patient satisfaction was higher due to early rehabilitation and reduced soft tissue damage without increasing the complication frequency.

This study was undertaken to assess the feasibility of a new subtrochanteric osteotomy technique for total hip arthroplasty (THA) in cases with a high dislocated hip secondary to the sequelae of a septic hip in childhood. Eighteen patients (20 hips), aged 25 to 65 years (average 47.3 years), underwent THA using a cement-less conical stem (Cone prosthesis^®; Protek AG, Berne, Switzerland) with a new subtrochanteric osteotomy technique and were followed for an average of 23.6 months. All patients were graded as type III (high dislocation) according to the Hartofilakidis classification, and according to the Crowe classification 3 cases were of type III and 17 were of type IV.

The procedure was performed through a posterolateral approach and a provisional osteotomy was usually performed at the inferior half of the lesser trochanter. All acetabular component was inserted at the true acetabular and the acetabular cup was inserted in 5 cases and only a liner was inserted after cementing in 15 cases. The stem size and the amount of stem insertion was decided according to the preoperative planning and soft tissue tension. After final reduction, the greater trochanter was re-attached to the proximal femur with the hip in the abducted position. Cables or a grip system (Dall Miles^®, Stryker Orthopaedics Inc., Mahwah, NJ, USA) were used for fixation, and if possible, additional screws were inserted.

Postoperatively, range of motion exercises were encouraged after 2 to 3 weeks of bed rest and non-weight bearing crutch ambulation followed. Weight bearing was permitted only after obtaining radiological confirmation of bone union, but then active exercises were strongly encouraged to stretch abductors. Mean duration of surgery was 180.6 minutes, and mean perioperative blood loss was 1424.1ml. There were no intra-operative complications. Post-operative dislocation occurred in 2 cases and partial femoral nerve palsy developed in 1 case. Mean Harris Hip Score improved from 42.4 to 84.2. Mean lateral opening angle of acetabular cup and liner was 34.7 0 and mean anteversion was 20.8 0. All femoral components were implanted in neutral to 5 degrees of valgus, and mean leg lengthening was 36.5mm. The mean time to greater trochanter union was 3.72 months.

Primary THA in highly dislocated hips due to the sequelae of septic hip in childhood using the described subtrochanteric osteotomy and a cone prosthesis was found to be safe and effective at restoring leg length and trochanteric rotation. But more follow-up is required to more comprehensively establish the long-term results of the described procedure.

Audible squeaking following ceramic-on-ceramic total hip arthroplasty (THA) is a rare but troublesome problem. We retrospectively reviewed records of 1002 patients where a ceramic-on-ceramic THA had been done during the study period. Fifteen patients complained of squeaking, at any time following their arthroplasty. Fourteen of these 15 patients were evaluated clinically and radiologically. The demographics of these patients were compared to that of all the other patients who did not have squeaking following ceramic-on-ceramic THA. The radiographic data was compared to a control group matched for age, sex, body mass index (BMI), primary diagnosis, type of implant, date of surgery and length of follow-up.

There were 12 males and 2 females of a mean age of 44.5 years (range, 25–65 years). These 14 patients were found to have significantly higher BMI of 25.98 kg/m2 (range, 21.6–32.3 kg/m2) as compared to the other patients who had ceramic-on-ceramic THA (mean, 23.61 kg/m2; range, 15.8 –30.3 kg/m2) (p=0.005). The lateral opening angle was found to be significantly lower (mean, 34°; range 29°–40°) in these patients than the matched control group (mean, 38°; range 30°–41°) (p=0.016). Mean acetabular anteversion was 22° (range 9°–37°), which was not significantly different to that of the matched controls (mean 23°; range 2°–33°) (p=.957). Limb length shortening of more than 5mm was observed in 12 of the 14 (85.7%) patients as compared to only 4 of 14 (28.6%) patients in the matched control group. Two patients had intermittent squeaking while the other 12 had continuous squeaking. Flexion and sitting cross legged were identified as the movements which most commonly (11 of 12) resulted in squeaking. Mean Harris hip score (HHS) improved from 44 (range, 19–66) to 94 (range, 88–100) and most patients (13 of 14) were satisfied with the outcome of the surgery.

Thus the incidence of squeaking was found to be low (1.5%, 15 of 1002) in our series. We identified high BMI, decreased lateral opening angle and limb length shortening as factors associated with occurrence of squeaking. Proper patient selection, implant placement, and avoidance of limb length discrepancy are likely to further reduce the incidence of this complication of ceramic-on-ceramic THA.

Introduction: Intradiscal electrothermal therapy (IDET) is a controversial, new treatment for low back pain, whose efficacy has not been tested in randomized trials. The present study was undertaken to compare the efficacy of IDET with that of a placebo treatment.

Methods: Patients were recruited by referral and by advertising in the media. Of 4,530 individuals who enquired, 1,360 were prepared to submit to randomization. Of these, 260 were found potentially eligible after clinical examination, and 64 became eligible after discography. All had discogenic low back pain lasting longer than 6 months, with no comorbidity. Thirty-seven were allocated to IDET, and 27 to sham therapy. Both groups were satisfactorily matched for demographic and clinical features. IDET was performed using a standard protocol, in which the posterior annulus of the painful disc was heated to 90°C. Sham therapy consisted of introducing a needle onto the disc and exposing the patient to the same visual and auditory environment as for a real procedure. Follow-up at 6 months was achieved in over 85% of patients. Pain and disability were assessed using a visual analog scale for pain, the SF-36, the Oswestry disability scale, and the Back Depression Inventory.

Results: Patients in both groups exhibited improvements, but improvements in pain, disability, and depression, were significantly greater in the group treated with IDET. Pain scores improved by 24 points in the IDET group compared with 11 in the sham group. Oswestry scores improved by 11 in the IDET group, but only by 4 in the sham group. More patients deteriorated when subjected to sham treatment, whereas eight patients (25%) achieved greater than 75% relief of pain following IDET. Only one patient did so after sham treatment. The number needed to treat, to achieve 75% relief of pain, was 5. No patient suffered any adverse effects.

Discussion: IDET fails to provide relief in some 50% of patients. Consequently, its efficacy is difficult to demonstrate statistically. Nevertheless, IDET provides satisfying relief in a substantial proportion of patients. Non-specific factors account for a large proportion of the apparent efficacy of IDET, but its efficacy cannot be attributed wholly to a placebo effect. The efficacy of IDET may be related critically to patient selection and the technique used. Improvements in either of these areas may improve the effect-size of IDET. Meanwhile, IDET is a low risk procedure that constitutes a legitimate option for patients with discogenic low back pain whose only alternative is fusion.

INTRODUCTION: Intradiscal electrothermal therapy (IDET) is a controversial, new treatment for low back pain, whose efficacy has not been tested in randomised trials. The present study was undertaken to compare the efficacy of IDET with that of a placebo treatment.

METHODS: Patients were recruited by referral and by advertising in the media. Of 4,530 individuals who enquired, 1,360 were prepared to submit to randomisation. Of these, 260 were found potentially eligible after clinical examination, and 64 became eligible after discography. All had discogenic low back pain lasting longer than six months, with no co-morbidity. Thirty-seven were allocated to IDET, and 27 to sham therapy. Both groups were satisfactorily matched for demographic and clinical features. IDET was performed using a standard protocol, in which the posterior annulus of the painful disc was heated to 90°C. Sham therapy consisted of introducing a needle on to the disc and exposing the patient to the same visual and auditory environment as for a real procedure. Follow-up at six months was achieved in over 85% of patients. Pain and disability were assessed using a visual analog scale for pain, the SF-36, the Oswestry disability scale, and the Back Depression Inventory.

RESULTS: Patients in both groups exhibited improvements, but improvements in pain, disability, and depression, were significantly greater in the group treated with IDET. Pain scores improved by 24 points in the IDET group compared with 11 in the sham group. Oswestry scores improved by 11 in the IDET group, but only by four in the sham group. More patients deteriorated when subjected to sham treatment, whereas eight patients (25%) achieved greater than 75% relief of pain following IDET. Only one patient did so after sham treatment. The number needed to treat, to achieve 75% relief of pain, was five. No patient suffered any adverse effects.

DISCUSSION: IDET fails to provide relief in some 50% of patients. Consequently, its efficacy is difficult to demonstrate statistically. Nevertheless, IDET provides satisfying relief in a substantial proportion of patients. Non-specific factors account for a large proportion of the apparent efficacy of IDET, but its efficacy cannot be attributed wholly to a placebo effect. The efficacy of IDET may be related critically to patient selection and the technique used. Improvements in either of these areas may improve the effect-size of IDET. Meanwhile, IDET is a low risk procedure that constitutes a legitimate option for patients with discogenic low back pain whose only alternative is fusion.