Abstract

Shoulder replacements have evolved and current 4th generation implants allow intraoperative flexibility to perform anatomic, reverse, trauma, and revision shoulder arthroplasty. Despite high success rates with shoulder arthroplasty, complication rates high as 10–15% have been reported and progressive glenoid loosening remains a concern.

Abstract

The LockDown device (previously called Surgilig) is a braided polyester mesh which is mostly used to reconstruct the dislocated acromioclavicular joint. More than 11 000 have been implanted worldwide. Little is known about the tissue reaction to the device nor to its wear products when implanted in an extra-articular site in humans. This is of importance as an adverse immunological reaction could result in osteolysis or damage to the local tissues, thereby affecting the longevity of the implant.

We analysed the histology of five LockDown implants retrieved from five patients over the last seven years by one of the senior authors. Routine analysis was carried out in all five cases and immunohistochemistry in one.

The LockDown device acts as a scaffold for connective tissue which forms an investing fibrous pseudoligament. The immunological response at the histological level seems favourable with a limited histiocytic and giant cell response to micron-sized wear particles. The connective tissue envelope around the implant is less organised than a native ligament.

Cite this article: Bone Joint J 2015;97-B:83–8.

Osteochondral lesions (OCL) of the talus occur in 38% of the patients with supination external rotation type IV ankle fractures and 6 % of ankle sprains. Osteoarthritis is reported subsequently in 8–48% of the ankles. Several marrow stimulation methods have been used to treat the symptomatic lesion, including arthroscopic debridement and micro fracture. Encouraging midterm results have been reported, but longterm outcome is unknown in relation to more invasive treatments such as transfer of autologous osteoarticular tissue from the knee or talus (OATS), autologous chondrocyte implantation (ACI), frozen and fresh allograft transplantation.

Total Elbow Replacements are indicated for pain and disability in patients with rheumatoid and osteoarthritis of the elbow. The quality of the cementation has been specifically studied and shown to be directly related to the clinical outcome and implant survival.

Degenerative joint disease (DJD) involves the proteolysis of many extracellular matrix molecules (ECM) present in articular cartilage and other joint tissues such as tendon, meniscus and ligaments. Recent research has identified key enzymes involved in the catabolism of ECM. Two classes of enzyme the Matrix Metalloproteinases (MMP’s) MMP-2, MMP-3, MMP-13 and the ADAMTS family (a disintegrin and metalloproteinase with thrombospondin motifs) of proteinases most notably, ADAMTS-1, -4 and −5, have been shown to be involved in the catabolism of ECM (such as type II collagen and cartilage aggrecan). The presence of several MMPs in the synovial fluid has been reported; however, little data has yet been gathered on the presence of ADAMTS-1, -4 or −5 (the aggrecanases) in synovial fluids. In this study we have used a recombinant artificial substrate and specific neoepitope antibodies that recognise either MMP- generated or aggrecanase -generated degradation products to measure the relative activity of these two enzyme families in the synovial fluid from human patients.

Methods: A recombinant substrate containing the interglobular domain of cartilage aggrecan , flanked by a complement regulator and the Fc region of IgG has been stably transfected into CHO cells. The recombinant protein has been purified from the medium using a Protein A column followed by gel chromatography using a Superose 12 column. Synovial fluid samples were depleted of serum immunoglobulin by pre-absorption with ProSepA. The recombinant substrate was then added to synovial fluid samples and incubated overnight as 37?C. The recombinant substrate was recovered from samples using ProsepA and then separated by SDS-PAGE (10% gels). Gels were transferred to nitrocellulose membranes and immunoblotted with antibodies recognising the undigested substrate and using neoeptiope antibodies specifically recognising MMP or aggrecanase –generated catabolites.

Results: Preliminary analysis by Western blot using the anti IGD neoepitopes BC-14 (detecting cleavage at the major MMP site) and BC-3 (detecting cleavage at the aggrecanase site) demonstrated that enzymes in human synovial fluid collected from patients diagnosed with rheumatoid arthritis cleaved the pro-drug at the MMP site with little or no evidence of aggrecanase catabolism. In contrast, synovial fluid collected from patients diagnosed with osteoarthritis indicted that there was cleavage at the aggrecanase site. In these preliminary studies we have also examined the enzyme activity in a set of clinical samples collected from patients that have undergone knee replacement surgery having been given either n-3 fatty acids or a placebo 10 weeks prior to surgery. Results indicate that aggrecanase generated fragments were found in synovial fluid from placebo patients, and reduced levels of enzyme activity were apparent in fluids tested from patients that had received n-3 fatty acids prior to surgery.

Discussion: This data suggests that the recombinant substrate will aid in the detection of MMP or aggrecanase activities in synovial fluid samples. The ratio of MMP to aggrecanase activity has potential as a biomarker for the severity of cartilage degeneration in degenerative joint diseases.

Traditionally midshaft clavicle fractures have been treated conservatively. It is recognized that displaced and shortened fractures may be better treated operatively. In particular, patients with greater than 20 mm of shortening and 100 percent displacement have a symptomatic non union rate of 30 percent. The standard technique used previously has been via plate fixation with LC-DCP or DCP. However in the last 5 years intramedullary fixation has been popularized. “Rockwood intramedulary clavicular pin” remedies the past treatment issues including poor blood supply, painful prominent hardware and stress raiser related to removal of metal work.

Aim: The aim of this study was to assess the functional outcome following intramedullary fixation of clavicle using Rockwood pin.

Method: We retrospectively evaluated 17 patients with displaced and shortened mid-shaft clavicular fractures who underwent intramedullary pinning using Rock-wood pins. Each patient was assessed using the ASES, Constant and SF36 scoring system. A physical examination was performed and individual radiographs were assessed to determine union.

Results: The mean age of the patients was 28 (range 15–56). All patients went into union within 2 to 4 months. They had a shorter stay in hospital, earlier mobilization and no scar related paraesthesia. The average ASES score 98.2 (range 92–100) and constant 95.3 (range 89–100).

Summary: Displaced and shortened mid clavicular fractures require operative fixation. Plates and screws on the clavicle requires significant soft tissue stripping leading to compromised blood supply to the bone and multiple bi-cortical screws act as stress raisers. Previous intra-medullary devices presented with the problem of pin migration. Rockwood pins are designed with a differential pitch which leads to compression at the fracture site and prevent pin migration. From this study we now recommend the use of the Rockwood Pin for the management of displaced mid-shaft clavicle fractures.

Aim: To assess the functional outcome following internal fixation with the PHILOS® plating system for displaced proximal humeral fractures by using the ASES and Constant scoring system.

Background: Controversy exists with regards to the management of displaced proximal humeral fractures and many methods of treatment have been proposed over the years. In particular, the role of surgery has not been clearly defined. The current trend is toward limited dissection of the soft tissues with the use of minimal amounts of hardware to gain stability.

Methods: We performed a retrospective analysis of 30 consecutive patients treated surgically with the PHILOS ® plate for a displaced proximal humeral fracture between February 2002 and October 2003. Patients were assessed clinically and radio graphically at an average follow-up time of 9 months. Functional outcome was determined utilising the American Shoulder and Elbow Society score (ASES) and Constant Murley score. The injury was classified using Neer’s 4 part classification.

Results: Average age of the patients was 58 years (19 to 92). There were 6 two part, 14 three part and 10 four part fractures. All the fractures were radio graphically united by 10 weeks. The average overall ASES score is 66.5%. The average overall Constant score is 55%. The average external rotation at 90 of abduction for the ages 15–55 was 55°–64° and the ages 56–95 was 25°–34°. The average forward elevation for the ages 15–55 was 85°–95° and the ages 76–95 was 55°–64°. The most difficult movement for the older subgroup of patients was internal rotation which was up to the sacrum.

Conclusion: Our results show that good fracture stability and functional outcome can be obtained from the use of the PHILOS® plate. Early mobilisation of the shoulder can be achieved without compromising fracture union. We would recommend the use of the PHILOS® plate for the management of displaced fractures of the proximal humerus.