MRI signal intensity of anterior cruciate ligament graft after transtibial versus anteromedial portal technique (TRANSIG): A randomised controlled clinical trial.

BACKGROUND: Two primary surgical femoral drilling techniques are used to reconstruct the anterior cruciate ligament (ACL): the transtibial (TT) technique and the anteromedial portal (AMP) technique. Currently there is no consensus on which surgical technique elicits the best clinical and functional outcomes. MRI-derived measures of the signal intensity (SI) of the ACL graft have been described as an independent predictor of graft properties. The purpose of this study was to assess MRI-derived SI measurements of the ACL graft one year after ACL reconstruction, in order to compare graft maturation of both AMP and TT ACL reconstruction techniques. METHODS: This randomised controlled trial included 33 patients admitted for primary unilateral ACL reconstruction. Primary outcome was MRI Signal intensity ratio (SIR) of the ACL graft one year after ACL reconstruction. Differences in MRI SIR were assessed on two MRI sequencies: sagittal Proton Density Turbo Spin Echo weighted images (PDTSE) and 3D T2 Gradient Echo (T2*) weighted images. Analysis of interobserver and intraobserver variability was conducted for the SIR measurements. RESULTS: No difference in signal intensity of the graft was found between the TT and AMP techniques one year after ACL reconstruction (PDTSE p = 0.665, T2* p = 0.957). Both interobserver and intraobserver variability showed strong agreement (ICC 0.64-0.94). CONCLUSION: No differences in signal intensity of the graft on MRI were seen between the femoral drilling techniques one year after ACL reconstruction, suggesting similar graft maturation at that time. Follow-up studies are needed to determine whether graft intensity changes in the long term. LEVEL OF EVIDENCE: Therapeutic study with level of evidence I.

Dislocation after Posterior Stabilized Primary Total Knee Replacement: A Rare Complication in Four Cases.

INTRODUCTION: Dislocation of a total knee arthroplasty is a rare complication that has rarely been described, while the total knee arthroplasty is frequently performed. From literature, we know patient-related factors, like obesity, neuropsychiatric disease, and severe valgus or varus deformity, are associated with higher risk of dislocation. We show our cases for awareness of the risk factors for surgeons. Case Presentations. We present four patients with a dislocation after a total knee arthroplasty. We compare these case reports with previous literature and show the most important risk factors for these dislocations. In our cases, three of them suffered from obesity, which possibly has contributed to the dislocation. Three patients did have instability which emphasizes the importance of ligament balancing while performing a total knee replacement. In all cases, an exchange of the polyethylene liner was performed. CONCLUSION: Implant-related factors and surgical technique as well as patient-related factors can contribute to this uncommon complication. Obesity, neuropsychiatric disorders, and a severe valgus or varus deformity are important patient-related risk factors. Our cases show these risk factors too. Some of these risk factors were encountered as well as other comorbidity factors. Such risk factors must be taken into consideration when deciding whether to perform a total knee arthroplasty. This stresses the importance of patient education and shared decision-making before performing a total knee replacement.

Intrathoracic migration of a K-wire after percutaneous fixation of a proximal humerus fracture.

Proximal humerus fractures are common in elderly patients. Not all patient are fit for major surgery. Percutaneous fixation can be a suitable option though surgeons should be aware of the risks and complications. This case is about a 90-year-old woman with a proximal humerus fracture. After closed anatomical reduction we performed percutaneous K-wire fixation of the humerus fracture with a single K-wire. Five days postoperatively the patient experienced increased pain and dyspnea due to a pneumothorax caused by intrathoracic migration of the K-wire. Percutaneous fixation can be a suitable treatment for low-maintenance and fragile patients but surgeons should act with caution. Multiple threaded K-wires with a bend-free end should be used to reduce the risk for loss of repositioning or migration of the K-wire.

[A locked knee without previous trauma]. / Knie op slot zonder voorafgaand trauma.

A 22-year-old female presented at our hospital with a spontaneous extension deficit of the left knee. Examination revealed a luxation of the semitendinosus tendon under an osteochondroma on the posteromedial side of the proximal tibia. The tendon was repositioned by flexion and endorotation of the knee. Subsequently, the osteochondroma was surgically resected to prevent recurrence of the complaints.

Pseudotumour incidence, cobalt levels and clinical outcome after large head metal-on-metal and conventional metal-on-polyethylene total hip arthroplasty: mid-term results of a randomised controlled trial.

We compared the incidence of pseudotumours after large head metal-on-metal (MoM) total hip arthroplasty (THA) with that after conventional metal-on-polyethylene (MoP) THA and assessed the predisposing factors to pseudotumour formation. From a previous randomised controlled trial which compared large head (38 mm to 60 mm) cementless MoM THA with conventional head (28 mm) cementless MoP THA, 93 patients (96 THAs: 41 MoM (21 males, 20 females, mean age of 64 years, standard deviation (sd) 4) and 55 MoP (25 males, 30 females, mean age of 65 years, sd 5) were recruited after a mean follow-up of 50 months (36 to 64). The incidence of pseudotumours, measured using a standardised CT protocol was 22 (53.7%) after MoM THA and 12 (21.8%) after MoP THA. Women with a MoM THA were more likely to develop a pseudotumour than those with a MoP THA (15 vs 7, odds ratio (OR) = 13.4, p < 0.001). There was a similar incidence of pseudotumours in men with MoM THAs and those with MoP THAs (7 vs 5, OR = 2.1, p = 0.30). Elevated cobalt levels (≥ 5 microgram/L) were only associated with pseudotumours in women with a MoM THA. There was no difference in mean Oxford and Harris hip scores between patients with a pseudotumour and those without. Contrary to popular belief, pseudotumours occur frequently around MoP THAs. Women with a MoM THA and an elevated cobalt level are at greatest risk. In this study, pseudotumours had no effect on the functional outcome after either large head MoM or conventional MoP THA.

A suspected genetic form of bilateral osteochondritis dissecans of the knee in a Dutch family.

Osteochondritis dissecans (OCD) mostly has an idiopathic origin, but syndromic and familial forms have been reported. Mutations of the aggrecan (ACAN) and COL9A2 genes are associated with familial OCD, but these patients present with syndromic features. This article describes a mother and a daughter who both have bilateral OCD of the medial femoral condyles, and the monozygotic twin sister of the mother who has confirmed unilateral OCD (and possible bilateral OCD) of the medial femoral condyle. No short stature or any other syndromic features were present. None of the syndromic features associated with ACAN or COL9A2 mutations or any other known syndromes were present in this case. This case suggests a possible unknown genetic anomaly.

High prevalence of pseudotumors in patients with a Birmingham Hip Resurfacing prosthesis: a prospective cohort study of one hundred and twenty-nine patients.

BACKGROUND: Recently, concern has emerged about pseudotumors (lesions that are neither malignant nor infective in the soft tissues surrounding total hip arthroplasty components) after hip arthroplasties with metal-on-metal bearings. Patients treated in our hospital for degenerative arthritis of the hip with a Birmingham Hip Resurfacing (BHR) prosthesis were invited to return for follow-up evaluation. The prevalence and clinical relevance of pseudotumors were investigated. Risk factors for pseudotumor formation were sought. METHODS: A single-center cross-sectional prospective cohort study was conducted and included all patients who received a BHR from 2005 to 2010 in Martini Hospital, Groningen, The Netherlands. Data were collected on patient and surgical characteristics, clinical hip outcome scores (Harris hip score and Oxford score), serum metal ion levels (cobalt and chromium), and radiographs. A computed tomographic scan (without metal suppression) was made. In patients who had a revision, tissue samples were histologically examined. RESULTS: Originally, there were 129 patients with 149 BHRs. Four patients (six hips; 4%) were lost to follow-up. Our final cohort consisted of 125 patients (143 hips). From this final cohort, eleven patients (twelve hips) had a revision, and three of them (three hips) had the revision before the present study was conducted. Seven patients (eight hips; 5.6%) had a revision because of a symptomatic pseudotumor. Survival analysis showed an implant survival rate of 87.5% at five years (failure was defined as a revision for any reason). A pseudotumor was found on computed tomography in thirty-nine patients (forty hips; 28%). Of those patients, ten (eleven hips; 28%) had complaints involving groin pain and discomfort, a noticeable mass, or paresthesia. Symptomatic pseudotumors were significantly larger than asymptomatic pseudotumors (a mean volume of 53.3 cm3 compared with 16.3 cm3; p = 0.05). A serum cobalt level of >85 nmol/L was a predictor for pseudotumor formation (odds ratio, 4.9). CONCLUSIONS: Pseudotumor formation occurred in 28% of hips after an average follow-up of forty-one months. Most pseudotumors (72.5%) were asymptomatic. Larger pseudotumors were associated with more complaints. Survival analysis showed an implant survival of 87.5% at five years. Failure occurred in 5.6% (eight) of 143 hips because of a symptomatic pseudotumor.

High incidence of complications and poor clinical outcome in the operative treatment of periprosthetic femoral fractures: An analysis of 71 cases.

BACKGROUND: The purpose of this observational study was to determine the clinical results of the operative treatment of periprosthetic femoral fractures over a long period of time. METHODS: The medical records of patients treated between 1993 and 2006 for a periprosthetic femoral fracture were obtained after a survey in two major hospitals. Radiographic evaluation was performed according to the Vancouver classification. All patients were contacted to fill out the Oxford hip score. RESULTS: A total of 80 PPFs were identified in 79 patients. For 71 patients with 71 fractures, medical records and radiographs were available. The mean age at the time of fracture was 73.4 years (range: 38-95 years). The mean interval between initial arthroplasty and the time of fracture was 6.3 years. As many as 44 fractures occurred in patients with primary hip arthroplasty (62%) and 27 fractures in patients with revision implants (38%). All but two patients were treated operatively and 34 patients (48%) suffered from a complication, leading to a re-operation in 22 cases (33%). The most frequent indication for re-operation was re-fracture or implant failure. Vancouver type-C fractures lead to re-operations in 52% of the cases (11 of 20). A total of 36 patients (51%) were able to complete an Oxford hip score after a mean period of 64.9 months (range: 16-157 months). The other patients were lost to follow-up (45% were deceased and 4% were mentally impaired). The mean Oxford hip score was 27.8 (range: 12-57) and was significantly higher in patients suffering from a complication (p=0.02) and in patients with a periprosthetic fracture (PPF) after revision surgery (p=0.02). CONCLUSION: The treatment of periprosthetic femoral fractures has a high complication rate and a large number of re-operations occur. The long-term clinical results are compromised by the event of a complication. The clinical results of treated fractures after a primary arthroplasty were better than after multiple arthroplasty procedures. Particularly, Vancouver type-C fractures showed high complication rates. This high complication rate should be taken into account for future studies in PPFs.

[A swollen leg after total hip arthroplasty]. / Een gezwollen been na totale heupartroplastiek.

Two patients, a 71-year-old and a 59-year old woman who had undergone total hip arthroplasty, presented with pain, difficulty in walking and slow progressive unilateral leg swelling. They did not have any other physical abnormalities. Physical examination and other investigations indicated a cystic enlargement of the iliopectineal bursa causing venous obstruction of the v. femoralis. After exploration and excision of the swelling the patients recovered rapidly. Pathological examination showed a bursa with an extensive foreign body giant cell reaction, double-breaking fibrous polyethylene and a small quantity of granular metal pigment originating from the total hip prosthesis. A unilateral swelling of the leg can also be caused by deep venous thrombosis and primary lymphatic oedema or by other compressing swellings. Venous obstruction due to cystic enlargement of the iliopectineal bursa following total hip arthroplasty is only described incidentally. Treatment consists of decompression of the affected structures and if necessary revision of the polyethylene cup to avoid excessive polyethylene wear.

[A 65-year-old patient with an odontoid fracture caused by 'headbanging']. / Een 65-jarige patiënte met een densfractuur veroorzaakt door 'headbangen'.

A 65-year-old woman who habitually made flexion-extension movements with her cervical vertebral column (so-called 'headbanging') was seen with complaints of the neck. X-rays of the neck revealed an odontoid fracture. Bone densitometry revealed lowered bone mineral density (osteopenia). The diagnosis was odontoid fracture due to headbanging, in the presence of osteopenia. Patient recovered after treatment with a neck collar worn for 6 months.

Alignment of the femoral component in a mobile-bearing unicompartmental knee arthroplasty: a study in 10 cadaver femora.

Use of an intramedullary rod is advised for the alignment of the femoral component of an Oxford phase-III prosthesis. There are users moving toward extramedullary alignment, which is merely an indicator of frustration with accuracy of intramedullary alignment. The results of our study with 10 cadaver femora demonstrate that use of a short and long intramedullary femoral rod may result in excessive flexion alignment error of the femoral component. Understanding of the extramedullary alignment possibility and experience with the visual alignment of the femoral drill guide is essential toward minimizing potential errors in the alignment of the femoral component.

[A swelling in the knee cavity, not caused by a Baker's cyst but by a nerve sheath tumour]. / Een zwelling in de knieholte, niet veroorzaakt door een baker-cyste, maar door een zenuwschedetumor.

In a woman, aged 30 years, who presented with a right popliteal mass, a Baker's cyst (popliteal cyst) was diagnosed. Five years later she developed symptoms that were attributed to compression of the peroneal nerve by the mass. Because of the troublesome nature of these symptoms, it was decided to excise the mass. Immediately after the operation, a complete loss offunction ofthe common peroneal nerve was apparent. Histopathologic examination revealed an ancient schwannoma (nerve sheath tumour). The most important reason for not having diagnosed the schwannoma was that it was not considered in the differential diagnosis of the popliteal mass. Although Baker's cysts are the most common popliteal masses, nerve sheath tumours should also be considered in the differential diagnosis.

[Medial unicompartmental knee prosthesis for patients with unicompartmental gonarthrosis]. / Mediale unicompartimentele knieprothese voor patiënten met unicompartimentele gonartrose.

The function and survival time of unicompartmental knee prostheses for patients with severe gonarthrosis have been improved the past few years by developments in their design, the instrumentarium and the surgical technique. A medial unicompartmental knee prosthesis may be indicated in patients with arthrosis of the medial tibiofemoral compartment. The prerequisites are an intact anterior cruciate ligament, an intact lateral compartment, a correctable varus axis and sufficient flexion in the knee. Contraindications are inflammatory arthropathies and a recent episode of septic arthritis. Relative contraindications are: old age, excess body weight, patellofemoral arthrosis and chondrocalcinosis. A unicompartmental knee prosthesis can be placed via a small parapatellar incision. The postoperative recovery is more rapid than following the classical open approach, while the knee function after 5 years is comparable. The knee function also seems better following a medial unicompartmental knee prosthesis than after valgusising tibial head osteotomy. The latter is still preferred for young active patients. Medial unicompartmental knee prostheses fail in 6-8% of patients. Revision to a total knee prosthesis is then the treatment of choice. In the long term, unicompartmental prostheses with a mobile bearing become loose less often than comparable prostheses with a fixed bearing.