Hakon Kofoed

ANKLE ARTHROPLASTY IN PATIENTS YOUNGER AND OLDER THAN 50 YEARS : A PROSPECTIVE SERIES WITH LONG-TERM FOLLOW-UP

One hundred consecutive cases treated with ankle arthroplasty for osteoarthritis (OA) or rheumatoid arthritis were followed prospectively and annually for up to 15 years. Survivorship analysis was performed, with the endpoint being prosthesis revision or change to arthrodesis. Patients who were younger than 50 years at the first implantation constituted one group (group A, 30 ankles). The other group (group B, 70 ankles) consisted of patients aged 50 years or older at the first implantation. All patients were assessed clinically according to the Kofoed Ankle Score. The distribution of OA/rheumatoid arthritis in group A was 18/12, and in group B it was 43/27 (not significant). The median age in group A was 46 years (range, 22–49 years), and in group B it was 63 years (range, 51–83 years). In group A, one case was revised, and three cases were converted to arthrodesis after a median of 5 years (range, 5–9 years). In group B, four cases were revised, and four cases were converted to arthrodesis after a median of 5.5 years (range, 2–8 years). The results of cases with traumatic OA did not differ between groups A and B. It was concluded that the results of ankle arthroplasty were of equal quality in patients younger than 50 years and those who were older.

Cylindrical Cemented Ankle Arthroplasty: A Prospective Series with Long-Term Follow-Up:

From 1981 to 1985 28 ankle arthrop! lasties were performed using a congruent and cylindrical ankle design. The talus component was an anatomically shaped cap to cover the talus dome and the facets. The tibial component was congruent toward the talus and had two parallel bars on the back for fixation into the distal tibia. The diagnosis was osteoarthritis in 15 cases and rheumatoid arthritis in 11 cases (two bilateral cases). There were seven failures, giving a cumulative estimated survival rate of 70% for the prosthesis at 12 years.

Bone mineral density, gait analysis, and patient satisfaction, before and after ankle arthroplasty

Bone mineral density (BMD) and patient satisfaction were measured and gait analysis was performed in patients treated with unilateral dual-coated ankle arthroplasty. The study comprised 14 patients (eight women and six men) measured preoperatively and at a median of 15 (range, 12–26) months after surgery. BMD was measured bilaterally in the distal tibia and in the calcaneus. A plantar pressure analysis was performed, including foot contact duration and a new index for describing the ground reaction force curve called the Valley Index (VI). The patients also evaluated their level of pain, ability to cope with daily activities, adaptation of shoes, and walking ability before surgery and at follow-up on a visual analogue scale (VAS). Bone mass significantly increased adjacent to the tibial part of the prosthesis. The patients experienced less pain and improved walking and performance in daily activities. There was also a decrease in foot contact duration as well as an increase in VI and ankle range of motion. Change in bone mass was the variable that correlated best with the patients evaluation of the general outcome of ankle arthroplasty. Correlations among other variables are described. The study concluded that a fairly simple analysis of the ground reaction force curve, bone mass measurements, and VAS can demonstrate that ankle arthroplasty is able to normalize gait, decrease foot contact duration, increase bone mass, and reduce pain.

Comminuted Displaced Colles' Fractures: Treatment with Intramedullary Methylmethacrylate Stabilisation

Four women aged 87, 77, 74 and 69 years with severely comminuted, displaced and intraarticular Colles fractures of the dominant hand, where conservative treatment had failed, were treated by use of intramedullary methylmethacrylate stabilisation in order to retain optimal anatomical position of the fracture. The patients were followed by serial clinical, radiological and 99Technetium-scintimetrical examinations for at least 1 year. Normal mobility of the wrist and power of the grip was obtained within 6 weeks postsurgery in all patients. Radiological cortical bone healing occurred within normal time and scintimetrically the fractures was healed within 6 weeks. No secondary displacement of the fractures occurred. It was concluded that this method might be considered in the treatment of certain severely comminuted and unstable Colles fractures as it seem to offer a quick rehabilitation and so far no late problems.

Failure of metal-backed patellar arthroplasty. 47 AGC total knees followed for at least 1 year

A prospective series of 47 total knee arthroplasties in 44 patients with gonarthrosis were followed for at least 1 year to detect patellar complications. In five knees the metal-backed patellar component failed, in one knee the cement fractured, and in one knee there was a spontaneous fracture of the patella. We regard this failure rate as unacceptable.

Prospective analysis of a first MTP total joint replacement. Evaluation by bone mineral densitometry, pedobarography, and visual analogue score for pain.

BACKGROUNDnWe hypothesized that a total replacement of the first metatarsophalangeal joint (MTP-1) would alter the walking pattern with medialisation of the ground reaction force (GRF) of the foot and subsequently cause an increase in bone mineral density (BMD) in the medial metatarsal bones and a decline of BMD in the lateral metatarsal bones.nnnMETHODSnTwelve patients receiving total joint replacements (Roto-Glide(®)) of MTP-1 were enrolled in a prospective cohort. BMD and pedobarography of the heel bone and the metatarsal heads were performed preoperatively and at least 12 months postoperatively.nnnRESULTSnBMD in the lateral metatarsals and GRF under the lateral column of the operated feet decreased significantly on the operated feet.nnnCONCLUSIONSnTotal joint replacement of MTP-1 tends to reduce GRF under the lateral column of the foot causing a corresponding decline in BMD and pedobarographic measures. Our findings support the further use of the Roto-Glide(®) prosthesis for osteoarthritis of the first metatarsophalangeal joint.

Concept and use of the Scandinavian total ankle replacement.

The hindfoot complex presents with a number of anatomical variations that should be taken into account when planning to perform an ankle replacement.” “ W hy is there so much fuss about replacing the ankle? It should be simple enough: the foot should be plantigrade with the heel directly under the lower leg, the ankle should be stable, and the mobility should be functional. This has in principle nothing to do with the implant. This is about corrective surgery and knowledge of the normal kinematics of the ankle joint. But looking at the history of ankle replacement, it is obvious that the results currently cannot match those of hip and knee replacements. There are of course several reasons for that. The hindfoot complex presents with a number of anatomical variations that should be taken into account when planning to perform an ankle replacement. The ankle prosthesis cannot solve all of these variations (varus, valgus, instability, ad latus displacement, bone quality, vascularization, diabetes, etc); they must be dealt with separately or simultaneously. This takes an experienced surgeon and thorough preoperative planning. Is there a general agreement about indications and contraindications? Should it be done in young persons, or should they have an arthrodesis? Is the prosthesis stable in itself? Who should perform the surgeries? Will instruments cover up for technical difficulties? Is any prosthesis superior to others? Is ankle replacement better than arthrodesis? Still more questions are to be answered. The functional outcome is not predictable but depends on several factors. The most important is the muscle power. Can that be regained after years of suboptimal use? Can tendons and ligaments adapt to the new situation? Will (painful) swelling ever go away? What kind of postoperative training should be used? While patients may be pain free in the ankle, could the entire foot complex be pain free? Do we have any leads or investigations to answer the questions? This article is about how to surgically solve alignment and stabilization with the Scandinavian Total Ankle Replacement (STAR) and to give clues about what we currently know.

Ankle replacement revision

Several European countries have an ankle replacement register. As they are not built the same way, have different scoring systems, and different definitions for outcomes, there is a need for harmonization to be able to compare results. EFAS now has a committee that should promote the same scoring system for foot and ankle diseases and outcomes of treatment throughout Europe. This should be a validated scoring system that should be used by everybody. Hopefully, this work can be accomplished quickly in order to incorporate it into new as well as existing registers. Another matter is the definition of an ankle replacement revision. Some define any procedure performed after the initial surgery as a revision, while others only define a revision as one that involves extraction of components. Also in this respect there are differences. This editorial is about the definition of what should be called a revision, and it is illustrated by examples.

Radiolucency adjacent to the tibial component in total knee arthroplasty.

This study determined the accuracy of standard radiographs in observing radiolucency adjacent to the tibial component in total knee arthroplasty. A model of the proximal tibia was used. Plastic sleeves of different heights were glued under the tibial tray to imitate radiolucency. By tilting the x-ray tube 1degrees at a time, an investigation was performed to determine how many degrees it would take to cover the heights of the different plastic sleeves. In a clinical study of patients at standard follow-up, 21 knees were examined using standard radiographs. Radiographs using image intensification were then taken of the same knees to obtain radiographs with views parallel to the plane of the tibial tray. The results of the study on the phantom showed that a 1degrees deviation of the x-ray beam from the optimal position would obscure a 0.5-mm radiolucency. This was true for radiolucencies of 2, 3, 4, and 5 mm. This was confirmed in the clinical study where < or = 4 mm of radiolucency was obscured on standard radiographs. Therefore, standard radiographs cannot be used to determine radiolucency. The 2-mm radiolucency normally associated with loosening is not clinically valid.

The Rotoglide™ total replacement of the first metatarso-phalangeal joint. A prospective series with 7–15 years clinico-radiological follow-up with survival analysis

BACKGROUNDnThe Rotoglide total replacement of the MTP-1 joint. 15 years survival analysis. The purpose of this prospective study was to evaluate the long-term performance clinico-radiographically of an uncemented three-component total replacement for the first metatarso-phalangeal joint (MTP-1) used for hallux rigidus (primary osteoarthritis grades 3 and 4). The follow-up was median 11.5 years (7-15).nnnMETHODSnThe AOFAS forefoot score was used preoperatively and at follow-up. Radiographs were taken weight-bearing in the AP-projection and in tip-toe standing in the lateral view. Arthrosis in the sesamoid junction, prosthetic loosening, subsidence (of prosthesis as well as sesamoids), and dorsiflexion were measured, recorded and subjected to multiple variance analysis. Survival analysis was performed for 15 years.nnnMATERIALnNinety implants in 80 patients (53 women and 27 men); median age 58 (41-76) were evaluated.nnnRESULTSnSix patients representing seven prostheses in situ had died from unrelated reason. The median preoperative AOFAS increased significantly from 40 to 95. The median gain was 45. Four replacements (4.4%) were extracted for other reasons than loosening. No aseptic loosenings were recorded. The survival rate at 15 years was 91.5% (83-100). Multiple variance analysis showed that arthrosis in the metatarso-sesamoid junction correlated with reduced AOFAS score.nnnCONCLUSIONnThe prosthesis has stood the test of time; the results justify its further use.