Clinical Review

Perilunate Injuries

Am J Orthop. 2015 September;44(9):E300-E302

References

1. Herzberg G, Comtet JJ, Linscheid RL, Amadio PC, Cooney WP, Stalder J. Perilunate dislocations and fracture-dislocations: a multicenter study. J Hand Surg Am. 1993;18(5):768-779.

2. Sotereanos DG, Mitsionis GJ, Giannakopoulos PN, Tomaino MM, Herndon JH. Perilunate dislocation and fracture dislocation: a critical analysis of the volar-dorsal approach. J Hand Surg Am. 1997;22(1):49-56.

3. Hildebrand KA, Ross DC, Patterson SD, Roth JH, MacDermid JC, King GJ. Dorsal perilunate dislocations and fracture-dislocations: questionnaire, clinical, and radiographic evaluation. J Hand Surg Am. 2000;25(6):1069-1079.

4. Kremer T, Wendt M, Riedel K, Sauerbier M, Germann G, Bickert B. Open reduction for perilunate injuries--clinical outcome and patient satisfaction. J Hand Surg Am. 2010;35(10):1599-1606.

5. Forli A, Courvoisier A, Wimsey S, Corcella D, Moutet F. Perilunate dislocations and transscaphoid perilunate fracture-dislocations: a retrospective study with minimum ten-year follow-up. J Hand Surg Am. 2010;35(1):62-68.

6. Gilula LA. Carpal injuries: analytic approach and case exercises. AJR Am J Roentgenol. 1979;133(3):503-517.

7. Kozin SH. Perilunate injuries: diagnosis and treatment. J Am Acad Orthop Surg. 1998;6(2):114-120.

8. Graham TJ. The inferior arc injury: an addition to the family of complex carpal fracture-dislocation patterns. Am J Orthop. 2003;32(9 suppl):10-19.

9. Mayfield JK, Johnson RP, Kilcoyne RK. Carpal dislocations: pathomechanics and progressive perilunar instability. J Hand Surg Am. 1980;5(3):226-241.

10. Mayfield JK. Mechanism of carpal injuries. Clin Orthop Relat Res. 1980;149:45-54.

11. Adkison JW, Chapman MW. Treatment of acute lunate and perilunate dislocations. Clin Orthop Relat Res. 1982;164:199-207.

12. Souer JS, Rutgers M, Andermahr J, Jupiter JB, Ring D. Perilunate fracture-dislocations of the wrist: comparison of temporary screw versus K-wire fixation. J Hand Surg Am. 2007;32(3):318-325.

13. Başar H, Başar B, Erol B, Tetik C. Isolated volar surgical approach for the treatment of perilunate and lunate dislocations. Indian J Orthop. 2014;48(3):301-315.

14. Komurcu M, Kürklü M, Ozturan KE, Mahirogullari M, Basbozkurt M. Early and delayed treatment of dorsal transscaphoid perilunate fracture-dislocations. J Orthop Trauma. 2008;22:535-540.

15. Massoud AH, Naam NH. Functional outcome of open reduction of chronic perilunate injuries. J Hand Surg Am. 2012;37(9):1852-1860.

Once open reduction is undertaken, a dorsal, volar, and combined approach can be used.^2-4 In most cases the dorsal approach is selected first. A longitudinal incision is made over the dorsum of the wrist, centered on the Lister tubercle. Dissection occurs between the third and fourth dorsal compartments. After the capsule is exposed, reduction of the lunate to the capitate is confirmed. If any fractures are present in the carpus (eg, scaphoid), they are internally fixed. The scapholunate articulation is then addressed. In general, the scapholunate ligament is not disrupted with a transscaphoid perilunate dislocation. However, if the scapholunate ligament is disrupted, the joint should be reduced and pinned. Repair or reconstruction of the scapholunate ligament is performed. Finally, the lunotriquetral articulation is reduced and stabilized with pins. There are no studies that specifically suggest direct repair of the lunotriquetral ligament versus pinning of the lunotriquetral articulation, but the lunotriquetral ligament could be repaired in similar fashion to the scapholunate ligament at the surgeon’s discretion.

As an alternative to percutaneous pinning, intercarpal screw fixation can be used to stabilize the carpus. A 2007 study by Souer and colleagues¹² showed no substantial difference in outcome between the 2 methods of fixation. However, a second procedure is required to remove the screws.

The volar approach, if selected, is typically done second and performed via an extended carpal tunnel incision. It allows decompression of the carpal tunnel and enables repair of volar capsular ligaments (ie, long and short radiolunate ligaments, volar scapholunate ligament, and volar lunotriquetral ligament), which increases overall carpal stability. Currently, many surgeons favor a combined dorsal-volar approach for its efficacy.^2,3 Some use a dorsal approach in all patients and perform a volar procedure only if the patient has median nerve symptoms.⁴ However, Başar and colleagues¹³ report use of only the volar approach for treatment of perilunate injuries. The authors repaired the long and short radiolunate ligaments, volar scapholunate ligament, and volar lunotriquetral ligament. They reported reasonably good outcomes, which are equivalent to those reported in similar studies using dorsal or combined dorsal-volar approaches. However, no studies in the literature directly compare any of the different approaches with each other.

Postoperatively, patients are placed in a long-arm thumb-spica cast for 4 weeks, and then in a short-arm cast for 4 to 8 weeks (Figure 2). If present, pins are removed in 3 to 12 weeks, with most authors recommending removal at 8 weeks.^2,14

Lastly, carpal tunnel symptoms can develop late and even after a successful reduction and surgical stabilization. One theory is that a significant perilunate injury can create slightly higher baseline carpal tunnel pressures, which can compromise the blood flow to the median nerve and cause carpal tunnel symptoms. Additionally, it is possible that direct median nerve contusion and/or traction injury via a displaced lunate can also cause these symptoms. Whatever the inciting cause of median-nerve irritation, a delayed carpal tunnel release is sometimes required.

Conclusion

Outcomes after either perilunate or lunate dislocation are fair to good at best but can be optimized with prompt, appropriate treatment. Closed reduction and casting as definitive treatment has been abandoned because of frequent loss of reduction.¹² Early open reduction (ie, less than 3 days after injury) has been shown to be beneficial.^1,2 However, even those treated early and with anatomic restoration of carpal alignment can expect a loss of grip strength and a range of motion of approximately 70% compared with the contralateral side.^2-5 A recent study has suggested that lesser-arc injures generally have a poorer overall outcome than their greater-arc counterparts.¹⁵

More than half of all patients with perilunate injuries will develop radiographic signs of osteoarthritis, and some will require additional salvage procedures.3-5 Kremer and colleagues4 showed that overall results after perilunate injuries deteriorate with time. However, according to a paper by Forli and colleagues5 in which patients were followed a minimum of 10 years after their injuries, the authors found that, despite radiographic progression of arthritis, most patients maintained reasonable hand function.