The treatment of acute full thickness chondral damage within the knee is a surgical challenge. Frequently used surgical techniques include chondroplasty, micro-fracture and chondrocyte implantation. These procedures give unpredictable functional outcomes and if the formation of neocartilage is achieved it is predominantly composed of type 1 collagen. The TruFit osteochondral plug was designed to provide a scaffold for cell proliferation into full thickness chondral defects. It is a composite polymer composed of polylactide co-glycolide, calcium sulphate and poly-glycolide fibres. It is composed of 2 layers, one with a similar trabecular network to cancellous bone and a superficial layer designed to simulate articular lining. The TruFit bone plug was analysed using micro-computed tomography. Its morphology characteristics, granulometry, mechanical performance and image guided failure were tested as well as numerical modelling to assess the permeability of TruFit. Morphological parameters of the TruFit bone plug compared favourably with those of human tissue. Under load the scaffold exhibited shear bands throughout the composite leading to a failure mechanism similar to cancellous bone. Stress relaxation rates of the scaffolds were greatly decreased under wet conditions, likely due to plasticisation of the scaffold by water. The biomechanical properties of the TruFit bone plugs are a cause for concern. The Scaffolds mechanical performance under load rapidly deteriorates in wet conditions at body temperature (the natural knee environment). This early failure will lead to defects in the articular surface where the plug has been inserted. Clinical data is sparse. This study correlates with work performed by Dockery et al & Spalding et al. These clinical studies have shown that the TruFit implant shows no evidence of bone ingrowth or osteoconductivity. It provides no subchondral support to neocartilage or tissue that was stimulated to form around the defects and surgical sites

The purpose of this study was to evaluate the risk of late displacement after the treatment of distal radial fractures with a locking volar plate, and to investigate the clinical and radiological factors that might correlate with re-displacement. From March 2007 to October 2009, 120 of an original cohort of 132 female patients with unstable fractures of the distal radius were treated with a volar locking plate, and were studied over a follow-up period of six months. In the immediate post-operative and final follow-up radiographs, late displacement was evaluated as judged by ulnar variance, radial inclination, and dorsal angulation. We also analysed the correlation of a variety of clinical and radiological factors with re-displacement. Ulnar variance was significantly overcorrected (p < 0.001) while radial inclination and dorsal angulation were undercorrected when compared statistically (p <  0.001) with the unaffected side in the immediate post-operative stage. During follow-up, radial shortening and dorsal angulation progressed statistically, but none had a value beyond the acceptable range. Bone mineral density measured at the proximal femur and the position of the screws in the subchondral region, correlated with slight progressive radial shortening, which was not clinically relevant.

Volar locking plating of distal radial fractures is a reliable form of treatment without substantial late displacement.

Cite this article: Bone Joint J 2013;95-B:396–400.

Objective: Unicompartmental knee arthropasty (UKA) has recently attracted increased popularity and usage, though issues exist regarding tibial component failure. UKA instability may be due to insufficient bony support at the proximal tibia. Pre-operative knowledge of ‘safe’ resurfacing depths offering subchondral bony support could help minimize UKA instability. We recently developed a novel CT imaging tool (CTTOMASD) which assesses subchondral bone mineral density (BMD) in relation to depth from the subchondral surface. The objective of this work was to determine the in-vivo precision of CT-TOMASD safe resurfacing depths in human tibial compartments. Seven knees from seven donors (2M:5F; age:46+/−11) were scanned three times via QCT (GE Lightspeed; BMD Phantom; 0.625x0.625x0.625mm resolution). CTTOMASD regional analyses were performed for medial and lateral compartments; outputting density versus depth plots fit with polynomial regression equations. As density decreases with increased depth from the subchondral surface, a density threshold of 300mg/ cm3 was arbitrarily set to correspond with the safe resurfacing depth. The 300mg/cm3 density threshold corresponds to the average density of subchondral trabecular bone, and is ~2x the density of weak epiphyseal trabecular bone located beneath stiffer subchondral trabecular bone. Precision was defined using coefficients of variation (CV%). In-vivo precision errors associated with CT-TOMASD safe resurfacing depths were less than 2.7%. CV% was 2.7% for the medial compartment depth and 2.6% for the lateral compartment depth. CT-TOMASD demonstrates repeatable measures of safe resurfacing depths invivo. Safe resurfacing depths are measured in relation to defined density thresholds which can be adjusted according to UKA design and patient specifics (e.g., size, sex). CT induces a low radiation dosage due to the low presence of radiosensitive tissues at the knee (~1/10th of a long-leg standing radiograph). CT-TOMASD has potential to be used as a pre-operative imaging technique for improved UKA stability and longevity

The recent development of locking-plate technology has led to a potential revolution in the management of fractures of the distal radius. This review examines the evidence for pursuing anatomical restoration of the distal radius and the possible advantages and pitfalls of using volar locking plates to achieve this goal. The available evidence for adopting volar locking plates is presented and a number of important and, as yet unanswered, questions are highlighted.

In a randomised prospective study, 20 patients with intra-articular fractures of the distal radius underwent arthroscopically- and fluoroscopically-assisted reduction and external fixation plus percutaneous pinning. Another group of 20 patients with the same fracture characteristics underwent fluoroscopically-assisted reduction alone and external fixation plus percutaneous pinning. The patients were evaluated clinically and radiologically at follow-up of 24 months. The Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire and modified Mayo wrist score were used at 3, 9, 12 and 24 months postoperatively. In the arthroscopically- and fluoroscopically-assisted group, triangular fibrocartilage complex tears were found in 12 patients (60%), complete or incomplete scapholunate ligament tears in nine (45%), and lunotriquetral ligament tears in four (20%). They were treated either arthroscopically or by open operation. Patients who underwent arthroscopically- and fluoroscopically-assisted treatment had significantly better supination, extension and flexion at all time points than those who had fluoroscopically-assisted surgery. The mean DASH scores were similar for both groups at 24 months, whereas the difference in the mean modified Mayo wrist scores remained statistically significant.

Although the groups are small, it is clear that the addition of arthroscopy to the fluoroscopically-assisted treatment of intra-articular distal radius fractures improves the outcome. Better treatment of associated intra-articular injuries might also have been a reason for the improved outcome.

Purpose: A porous tantalum cylindrical shaped implant (Osteonecrosis Intervention Implant, Zimmer, Warsaw, IN) has been designed to provide subchondral bony support of the subchondral plate, be osteoconductive and allow revascularization of an osteonecrotic femoral head. This study evaluates retrieved implants obtained at the time of conversion to total hip arthroplasty to determine the ability of this device to fulfill its objectives. |. Methods: Eighteen femoral heads with the tantalum implant still in situ were evaluated with contact radiographs and scanning electron microscopy to assess femoral head and bony anatomy, bone growth into the implant and femoral head revascularization. Retrievals from 12 males and 6 females with an average age of 46 years old (range, 31–61) and Stage I or II osteonecrosis were evaluated. |. Results: At a mean of 13.4 months (range, 3–36) postoperatively, all femoral heads demonstrated subchondral collapse. The bone surrounding the implant remained necrotic with no evidence of revascularization or healing. Ingrowth was marginal and averaged less than 5%. Conclusions: This tantalum implant in its present design and surgical technique does not appear to uniformly provide structural support and promote healing of early osteonecrosis of the femoral head. This retrieval study suggests that successful results with this implant in certain cases of early osteonecrosis may be more attributable to the surgical technique requiring a core decompression, rather than the implant itself. |

A tantalum AVN implant was used in sixteen patients with advanced AVN (Grade 3/4). No reports have been published of use of this implant in advanced disease. Outcomes included radiological, SF36, Harris hip score and secondary surgeries. HHS improved from fifty-two to seventy. SF36 scores approached controls. At over one year average follow-up five patients are revised to THA, however, all hips except one have at least minor pain. Revisions occurred in older patients or those with 100% head involvement. In younger patients, with up to 50% head involvement, this technique seems to be a viable option for advanced AVN. Evaluation of tantalum AVN implants in patients with advanced AVN. In younger patients, with up to 50% hip head involvement, this technique seems to be a viable option for advanced AVN. Revisions in general are in older patients or those with 100% head involvement. Most treatment options have had poor outcomes with advanced AVN. Surgeons generally perform THA or core decompression in these cases. Market pressure for a non-vascularized option to fill the channel after decompression has resulted in new implants. A tantalum device has been designed to fill the post-core decompression channel to allow subchondral support. This is a minimally invasive procedure with theoretically low morbidity. The average orthopedic surgeon would have no difficulty in the use of this implant. HHS improved from fifty-two to seventy. SF36 scores were below age-matched controls. At over one-year average follow-up five patients are revised to THA, however, all hips except one have at least minor pain. Revisions in general are in older patients or those with 100% involvement. In younger patients, with up to 50% head involvement, this technique seems to be a viable option. This device was used in a prospective cohort of sixteen patients with advanced AVN (Grade 3/4) with femoral head fracture/collapse. Operative technique including reduction of the fracture allows for improved results. Outcomes included radiological parameters (advancing disease, placement, ingrowth), SF36, Harris hip score and secondary surgeries