Letter to the Editor of Arthritis & Rheumatism (not accepted - November 5^th, 2004), regarding the protective role of hypermobility on hand osteoarthritis.

Articular Hypermobility Is a Protective Factor for Hand Osteoarthritis:

comment on the article by Kraus et al.

To the Editor:

I read with great interest the article by Kraus et al (1) since their opinion contradicts in part the knowledge that joint hypermobility predisposes to premature osteoarthritis (OA), specially of the knees (2,3).

This paper is an excellent, well done study, which considered a large number of patients (1.043). We have seen more than 600 patients with JHS in the last four years and frequently see DIP joint OA in these patients. We presented a Poster at the October 2004 ACR Meeting in San Antonio, TX, regarding the clinical study of 230 JHS patients, which can be seen in our web page (4). In this study 6% had premature OA.

I agree with Kraus’ findings that the prevalence of OA of the MCP and PIP joints of people with joint hypermobility is less than in people without laxity, and that probably the reason lies in biomechanical factors. With Mac Clayton in our combined Ortho-Arthritis Meetings at the Denver Medical Center, about 15 years ago, we had the belief that decompression of the MCP joints in patients with Rheumatoid Arthritis (RA), after resection of the MCP joints to place Silastic implants, was protective for the PIP joints. The laxity of the tendons, after the resection of the MCP joints appeared to be protective for the distal joints. We studied hundreds of hand X-rays of RA patients after decompression and were convinced by the initial results, but unfortunately we never published such study. In this regard is interesting the report cited by Kraus, that grip strength and pinch are diminished in individuals with joint hypermobility (5) and that there are reports of increased OA of the PIP and MCP joints associated with increased grip strength (6,7).

I think that the same principle, laxity of tendons, both in MCP resection and in joint hypermobility, protects the PIP joints both in RA and OA. We are planning a study, in RA patients with associated JHS, to see if they have less involvement of the MCP and PIP joints (which probably is the case), as compared to RA patients without associated JHS.

JHS in most joints is associated with premature OA or faster progression OA and we have seen this also in our patients. The reason for this appears to be two fold: patients with JHS have fragile cartilages (due to the genetic collagen alteration) and the affected joints develop more wear and tear by having excessive mobility and misalignment. In knee OA, as described by Lohmander in women soccer players in Sweden (8), following the anterior cruciate ligament injury, more than 50% went on to develop knee OA years later.

From Kraus article it should not be inferred that hypermobility prevents OA. It is my belief that JHS predisposes to OA in most joints, except for the MCP and PIP joints, for the reasons stated above. In Kraus study, DIP joints could not be studied, because they were part of the inclusion criteria and they were present in all cases. If they were to be studied in hypermobile patients, I would predict that JHS is not protective for DIP OA. Kraus should not stated that articular hypermobility is a protective factor for hand osteoarthritis in general, instead he should have said that the joints actually protected by hypermobility are the MCP and PIP joints of the hands.

Jaime F Bravo MD, Department of Rheumatology, Clinica Arauco and San Juan de Dios Hospital

Santiago, Chile. jbravos@ctcinternet.cl

References:

1. Kraus VB, Li Y-J, Martin ER, Jordan JM, Renner JB, Doherty M, et al. Articular hypermobility is a protective factor for hand osteoarthritis. Arthritis Rheum 2004; 50:2178-83.

2. Bridges AJ, Smith E, Reid J. Joint hypermobility in adults referred to Rheumatology clinics. Ann Rheum Dis 1992; 51:793-6.

3. Sharma L, Lou C, Felson DT, Dunlop DD, Kirwan-Melis G, Hayes KW, et al. Laxity in healthy and osteoarthritic knees. Arthritis Rheum 1999; 42:861-70.

4. Rheumatological web page: www.reumatologia-dr-bravo.cl

5. Gamble JG, Mochizuki C, Rinsky LA. Trapeziometacarpal abnormalities in Ehlers-Danlos syndrome. J Hand Surg (Am) 1989;14:89-94.

6. Chaisson CE, Zhang Y, Sharma L, Kannel W, Felson DT. Grip strength and the risk of developing radiographic hand osteoarthritis: results from the Framingham Study. Arthritis Rheum 1999; 42:33-8.

7. Chaisson CE, Zhang Y, Sharma L, Felson DT. Higher grip strength increases the risk of incident radiographic osteoarthritis in proximal hand joints. Osteoarthritis Cartilage 2000; 8 Suppl A:S29-32.

8. Lohmander LS, Ostenberg A, Englund M, Roos H. High prevalence of knee osteoarthritis, pain and functional limitations in female soccer players twelve years later after anterior cruciate ligament injury. Arthritis Rheum 2004; 50:3145-52.