SeVeRe DegeNeRATION OF THe MeDIAl COllATeRAl lIgAMeNT IN HAllUx VAlgUS: A HISTOpATHOlOgIC STUDy IN 12 CONSeCUTIVe pATIeNTS Ittipol Prasitdumrong, MD1, Chamnanni Rungprai, MD1, Nitit Reeboonlarb, MD1, Tara Poonpracha, MD2, Phinit Phisitkul, MD3 ABSTRACT Objective: To determine the degree and location of degenerative changes of the medial collateral ligament of the first metatarsophalangeal joint, using the lateral collateral ligament as a control, in patients undergoing hallux valgus correction. Materials and Methods: A strip of medial and lateral collateral ligaments were biopsied from 12 consecutive patients (age 45 ± 4.8 years) with symptomatic hallux valgus. A blinded analysis of histopathology was performed by an experienced pathologist. Results: The medial collateral ligament was significantly more degenerated compared to the lateral collateral ligament (x2 = 23.41, DF = 2, p < 0.0001). There was no significant difference in degeneration between different parts of each ligament. Conclusion: Our study found generalized severe degeneration in the medial collateral ligament without proximal-distal predilection. This information may have implications in the management of medial soft tissue repair in hallux valgus correction. Keywords: Hallux Valgus; collateral ligament; degeneration The Authors received no financial support for this study. INTRODUCTION Hallux valgus was proposed by Carl Heuter in 18711 as a foot disorder characterized by lateral deviation of the first metatarsophalangeal joint and metatarsus primus varus (medial deviation of the first metatarsal), disloca-
1. Department of Orthopaedic Surgery, Phramongkutklao Hospital and College of Medicine, Bangkok, Thailand. 2. Department of Anatomical Pathology Phramongkutklao Hospital and College of Medicine, Bangkok, Thailand. 3. Department of Orthopaedic Surgery, University of Iowa Hospitals and Clinics, Iowa City, IA, USA. Corresponding Author: Chamnanni Rungprai, M.D. Department of Orthopaedic, Phramongkutklao Hospital and College of Medicine, Bangkok, Thailand 10400. Phone: 1-304-719-8606, +66-81-4216577 E-mail:
[email protected],
[email protected].
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tion of the metatarsal head from the hallux sesamoids, and pronation of the first metatarsal and hallux2,3. Hallux valgus is commonly thought to develop because of improper shoe wear4-7; however, this does not explain all cases as some patients developed disease without ever wearing shoes7. It was reported that the prevalence of hallux valgus in the adult shoe wearing population was approximately 33%8. Additional risk factors such as female gender and familial genetics have also been associated with the development of hallux valgus8,9. At the present time, the patho-mechanical etiology leading to the development of a hallux valgus deformity remains unclear and may be multifactorial. One of the most notable causes may be due to failure of the soft tissue structure at the great toe metatarsophalangeal joint, as the hallux valgus deformity increases after a surgical release of the medial collateral ligament10-13,18,19 or after acute ligament rupture14-17. There has been no uniform technique for the repair or reconstruction of the medial collateral ligament in hallux valgus correction20. The degree of medial collateral ligament degeneration and the exact location of it may affect the surgical strategy of the medial soft tissue repair. A cadaveric study has shown both mechanical and histological deterioration of the medial capsule in specimens with hallux valgus11-13. Another in vivo study demonstrated the presence of extensive chronic inflammation at the medial aspect of the first metatarsal head in patients who underwent hallux valgus correction21. At present, in patients with hallux valgus, the precise anatomic location of medial collateral ligament degeneration is unknown; this site may be at the proximal insertion, mid-substance, or distal insertion. Thus we proposed a histopathological study of the medial collateral degeneration in patients who underwent hallux valgus correction using the lateral collateral ligament as a control. We hypothesized that the medial collateral ligament would be more severely degenerated than the lateral collateral ligament. In addition, the severity of degeneration was cataloged for different proximal-distal aspects of the ligaments. We hypothesized that the proximal aspect of the medial collateral ligament would be more degenerated than other areas.
Severe Degeneration of the Medial Collateral Ligament in Hallux Valgus Table 1: Cumulative data of the entire medial and lateral collateral ligaments Location
Degree of degeneration
Total
Mild
Moderate
Severe
Medial
6
9
33
48
Lateral
22
16
10
48
Total
28
25
43
96
Table 2: Degeneration in each part of medial and lateral collateral ligaments Location (part)
Proximal
Middle
Distal
Degree of degeneration
Location (side) Medial
Lateral
Mild
2 (12.5%)
8 (50.0%)
Moderate
2 (12.5%)
5 (31.3%)
Severe
12 (75.0%)
3 (18.7%)
Mild
1 (6.3%)
5 (31.3%)
Moderate
4 (25.0%)
8 (50.0%)
Severe
11 (68.7%)
3 (18.7%)
Mild
3 (18.7%)
9 (56.3%)
Moderate
3 (18.7%)
3 (18.7%)
Severe
10 (62.5%)
4 (25.0%)
Figure 1. Numbers of specimens with degenerative change from medial and lateral collateral ligaments of the hallux.
MATeRIAlS AND MeTHODS Between July 2007 and May 2008, 12 women, mean age 45 ± 4.8 years, were recruited for this observational study. The study was approved by the institutional review board. All patients with symptomatic hallux valgus disease 18 years of age or older who received corrective surgery by the same surgeon (PP) at the Orthopaedic Department, Phramongkutklao Hospital and College of Medicine were included. All patients had intractable pain and failed conservative treatment for at least 6 months. Patients who had an associated underlying inflammatory disease, a history of trauma, or previous surgery were excluded from this study. All patients underwent corrective surgery using a modified Mau osteotomy technique and a lateral soft tissue release, unilaterally in 8 patients and bilaterally in 4 patients. Medial and lateral collateral ligaments were biopsied in 3mm-wide strips from the entire length of the ligament in the operating room and placed in 10% formalin solution immediately. Each capsule was divided into proximal, middle, and distal parts and randomly labeled from 1 to 3 by an orthopaedic fellow (IP) not involved in the histological evaluation. Hematoxylin and eosin stain and a light microscope was used to identify and grade the histopathology of each specimen by an experienced pathologist (TP) who was blinded to the location from which each specimen was obtained. Histopathological findings were classified into mild, moderate, and severe degeneration.
Figure 2. Numbers of specimens with degenerative change from medial and lateral collateral ligaments of the hallux divided into specific parts.
Mild degeneration was defined as increased vascularity, linear fibroblast formation, fibrosis, and collagenization. Moderate degeneration was defined as myxoid degeneration and severe degeneration was defined as chondroid metaplasia and calcium phosphate crystal deposition. Chi-square tests were used to test differences between medial and lateral collateral ligament degeneration. ReSUlTS All 12 patients had degeneration in both collateral ligaments according to our defined criteria. However, the degree of degeneration was more severe in the medial collateral ligament compared to the lateral side, as shown in Table 1 and Figure 1. There was a significant difference between medial and lateral collateral ligament degeneration (Chi-square = 23.41, DF = 2, p < 0.0001). There was no significant difference in degeneration in specimens among proximal, middle, and distal parts of medial and lateral collateral ligament (Chi-square = 1.84,
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I. Prasitdumrong, C. Rungprai, N. Reeboonlarb, T. Poonpracha, P. Phisitkul DF = 4, p = 0.76 and Chi-square = 3.75, DF = 4, p = 0.439 respectively) (Table 2 and Figure 2). DISCUSSION Degenerative changes are common in medial collateral ligaments of patients who undergo hallux valgus reconstruction. The incidence of severe degeneration was more than three times as common when compared to the lateral collateral ligament in the same patients. This is in agreement with a study by Uchiyama et al. who found more type III collagen within the medial collateral ligament obtained from cadavers with hallux valgus compared to normal specimens11. The degenerative change of the medial collateral ligament of the first metatarsophalangeal joint may be related to the pathomechanics of hallux valgus among other factors including osseous deformity of the first metatarsal head13, instability of the first tarsometatarsal joint22-23, genetic factors24, and shoe wear4-7. Hideji et al. found that medial soft tissues, especially the medial capsule, are crucial for maintaining stability of the first metatarsophalangeal joint from hallux valgus deformity10-11. In contrast to our hypothesis that the pathology of the medial collateral ligament should be more severe at the insertion on the medial aspect of the first metatarsal head, we found no difference in the degree of ligament degeneration among proximal insertion, mid-substance, or distal insertion. This information has not been described before. Wen et al. found significant degenerative change at the proximal insertion in biopsy specimens obtained from 123 patients but there was no information regarding other portions of the ligaments and there was no control group21. There is no consensus in the method of medial capsulorrhaphy25-27, which can be designed as a longitudinal cut, vertical cut at the mid-substance27, Y or T cut27,28, or L-cut27,29. We believed that the predilection of degeneration in certain portions of the ligament may A allow for refinement in the medial soft tissue technique as the degenerated portion could be excised prior to a repair. Unfortunately, this suggestion cannot be made due to the diffuse nature of the degeneration. This is in contrast to the traumatic hallux valgus for which repair should be made at the site of injury. Douglas et al. repaired patients with traumatic collateral ligament injury through its mid-substance using end-to-end technique with two D-Ethibond sutures16. The presence of severe degeneration of the medial collateral ligament may raise some concerns regarding the feasibility of the repair. Lui et al. described a technique using the extensor hallucis brevis tendon to reconstruct the medial collateral ligament in a patient after a failed hallux valgus correction with medial capsular plication20. The overall high success in the hallux
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valgus correction with wide varieties of soft tissue repair indicates that local tissue is adequate in the majority of cases despite the presence of degenerative changes. We believe that due to the complete correction of the hallux valgus deformity as well as the sesamoid subluxation, the medial collateral ligament may see less aberrant tension force. In addition, appropriate level of tensioning of the medial collateral ligament may promote remodeling of the degenerated collagen tissue and also provide an optimal level of corrective force against the valgus deformity30. Our data suggests that repair of the medial collateral ligament should only occur as an adjunctive procedure to osseous realignment. This study has some limitations due to small numbers of subjects and the fact that they are all female, which may limit the generalizability of the results. We also did not have normal tissue of medial collateral ligament and lateral collateral ligament in a healthy, age-matched control group to compare against. The degree of degeneration in the lateral collateral ligament in our study may be influenced by the abnormal mechanics and degenerative change that occurred due to the hallux valgus deformity causing the comparison to be less sensitive. However, a very strong statistical significance level (p < 0.0001) supports our main finding regarding the degree of medial collateral ligament degeneration. CONClUSION There was generalized severe degeneration in the medial collateral ligament of the patients who underwent hallux valgus correction. There was no proximal-distal predilection of the degeneration within the ligament. Our data suggests that the surgeon should rely on the repair of the medial collateral ligament only as an adjunctive procedure to osseous realignment. ACKNOWleDgeMeNT We acknowledge and extend our heartfelt gratitude to the following persons who have made the completion of this research possible: MVK scholarship, Phramongkutklao Hospital and College of Medicine; and Yubo Gao, PhD, for statistical support. 1. 2. 3.
ReFeReNCeS Coughlin MJ. Hallux valgus: J Bone Joint Surg [Am] 1996;78-A:932-66 Sander Ap, Snijders CJ, Bert Vl. Medial deviation of the first metatarsal head as a result of flexion forces in hallux valgus. Foot Ankle int. 1992;13:515-22 Kilmartin Te, Barrington Rl, Wallace WA. Metatarsus primus varus. A statistical study. J bone Joint Surg Br. 1991;73(6):937-40
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Sim-Fook l, Hodgson AR. A comparison of forms among the non-shoe and the shoe wearing Chinese population. J Bone Joint Surg 1958;40:1058-62 einarsdottir H, Troell S, Wykman A. Hallux valgus in ballet dancers. Foot Ankle Int. 1995;16(2):92-4 Menz HB, Morris Me. Footwear characteristics and foot problems in older people. Gerontology 2005;51(5):346-51 l. B. Shine. Incidence of hallux valgus in a partially shoe-wearing community. Br Med J. 1965 June 26; 1(5451): 1648–1650. Roddy e, Zhang W, Doherty M. Prevalence and associations of hallux valgus in a primary care population. Arthritis Rheum 2008 59(6): 857-862. McBride eD. A conservative operation for bunions: J Bone Joint Surg 1928;10:735-9 Hideji K, Zong-ping l, Harold B, Kai-Nan A. Role of medial capsule and transverse metatarsal ligament in hallux valgus deformity. Clinical orthopaedics and related research 1998;354:235-40 Uchiyama e, Kitaoka HB, luo Zp, grande Jp, Kura H, An KN. Pathomechanics of hallux valgus: biomechanical and immunohistochemical study. Foot Ankle Int. 1994;26:732-8 Bock p, Kristen KH, Kroner A, engel A. Hallux valgus and cartilage degeneration in the first metatarsophalangeal joint. J Bone Joint Surg Br. 2004;86:66973 Unger K, Rahimi F, Bareither D, Muehleman C. The relationship between articular cartilage degeneration and bone changes of the first metatarsophalangeal joint. J Foot Ankle Surg 2000;39:24-32 Kadakia AR, Molloy A. Current concepts review: traumatic disorders of the first metatarsophalangeal joint and sesamoid complex. Foot Ankle Int. 2011 Aug;32(8):834-9 Fabeck lg, Zekhnini C, Farrokh D, Descamps py, Delincé pe. Traumatic hallux valgus following rupture of the medial collateral ligament of the first metatarsophalangeal joint: a case report. J Foot Ankle Surg. 2002 Mar-Apr;41(2):125-8. Douglas Dp, Davidson DM, Robinson Je, Bedi Dg. Rupture of the medial collateral ligament of the first metatarsophalangeal joint in a professional soccer player. J Foot Ankle Surg. 1997 SepOct;36(5):388-90.
17. Bohay DR, Johnson KD, Manoli A 2nd. The traumatic bunion. Foot Ankle Int. 1996 Jul;17(7):383-7. 18. Kura H, luo Zp, Kitaoka HB, An KN. Role of medical capsule and transverse metatarsal ligament in hallux valgus deformity. Clin Orthop Relat Res. 1998 Sep;(354):235-40. 19. Mann RR, Coughlin MJ. Adult hallux valgus. St Louis: Mosby 1993. 20. lui TH, Chan KB. Technical tip: Reconstruction of medial collateral ligament in correction of hallux valgus deformity with primar y medial collateral ligamentous insufficiency. Foot Ankle Surg. 2012 Mar;18(1):66-73. Epub 2011 Feb 2. 21. Wen JM, Tong y, Han Fy, Sun yS, Sun WD, Sang ZC, Hu HW, lin xx, Wu xB, liang Z. Observation C on pathological changes of the medial aspect of the first metatarsal head of hallux valgus. Zhongguo Gu Shang. 2008 Dec;21(12):883-5. 22. Johnson K, Kile T. Hallux valgus due to cuneiformmetatarsal instability. J. Southern Orthop. Assoc. 3:273 –282, 1994. 23. Klaue K, Hansen S, Masquelet A. Clinical, quantitative assessment of first tarsometatarsal mobility in the sagittal plane and its relation to hallux valgus deformity. Foot Ankle Int. 15:9 –13, 1994. 24. piqu´e-Vidal C, Sol´ e MT, Antich J. Hallux valgus inheritance: pedigree research 350 patients with bunion deformity. J Foot Ankle Surg. 2007;46:149-54. 25. panchbhavi VK, Rapley J, Trevino Sg. First web space soft tissue release in bunion surgery: functional outcomes of a new technique. Foot Ankle Int. 2011 Mar;32(3):257-61. 26. Choi SJ, Kim BC, eun IS, Huh JW. Consideration of various medial capsulorrhaphy methods in hallux valgus surgery. J Korean Foot Ankle Soc. 2008 Jun;12(1):9-13. Korean. 27. Mann RA, Coughlin MJ. Surgery of the foot and ankle. 6th ed. St. Louis: C.V. Mosby, 1992.184-363. 28. Wenig JA, McCarthy DJ. Modified V-Y capsulorrhaphy in hallux abducto valgus surgery. J Am Podiatr Med Assoc. 1989 Mar;79(3):132-8. Review. 29. Salvi V, Tos l. L’osteochondrosi die sesamoidi: Arch Ortop 75:1294-1304, 1962. 30. James R, Kesturu g, Balian g, Chhabra AB. Tendon: biology, biomechanics, repair, growth factors, and evolving treatment options. J Hand Surg Am. 2008 Jan;33(1):102-12. Review.
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