A Case for Acute Proximal Row Carpectomy for Perilunate Injuries

Abstract

Background

Perilunate injuries are complex injuries typically arising from high-energy injuries to the wrist. Standard treatment involves open reduction and internal fixation with ligamentous reconstruction; however, outcomes are fraught with complications including pain, stiffness, and arthrosis. Several case reports have demonstrated the role of proximal row carpectomy as a salvage procedure for complex carpal trauma in the setting of significant cartilage injury or bone loss. The authors believe that proximal row carpectomy may be an appropriate acute treatment in certain patient populations, with functional results similar to those obtained with ligamentous reconstruction.

Methods

A retrospective review of two cases with perilunate dislocations managed with primary proximal row carpectomy are presented.

Results

At greater than 1-year follow-up, both patients had stable radiocarpal alignment. Quick-DASH scores were 22.7 and 27.3.

Conclusion

Primary proximal row carpectomy is a treatment option in the acute setting for perilunate injuries in elderly, lower-demand patients. Functional results are similar to those obtained with ligamentous reconstruction, with a shorter recovery period.

Level of Evidence: IV

Introduction

The scaphoid, lunate, and triquetrum make up the proximal carpal row of the wrist, commonly referred to as the intercalary segment. These three bones are linked via the scapholunate (SL) and lunotriquetral (LT) interosseous ligaments, respectively. These ligaments do not function in isolation; there is an extrinsic ligamentous complex that consists of volar and dorsal radiocarpal and ulnocarpal ligaments that provides additional stability to the proximal carpal row. Injuries to the wrist vary in severity by the degree and number of stabilizing ligaments disrupted.^1,2

Perilunate dislocations (PLD) typically arise from a high energy mechanism. The mechanism responsible for most scapholunate and perilunate injuries is wrist extension, ulnar deviation, and carpal supination.¹ Mayfield described a progression of perilunate instability, traveling from radial to ulnar around the lunate: stage I involves disruption of the scapholunate articulation, stage II adds lunocapitate disruption, stage III adds lunotriquetral disruption, and finally, stage IV involves dislocation of the lunate from the radius.¹ Conversely, wrist extension, radial deviation, and intercarpal pronation create a reverse-progression of intercarpal disruption, starting with lunotriquetral disruption and working from ulnar to radial.³ As such, isolated scapholunate and lunotriquetral ligament injuries are within the greater perilunate spectrum.

Perilunate dislocations can be described as greater arc or lesser arc injuries. Greater arc injury, also known as perilunate fracture dislocation (PLFD), involves fractures of the radius, ulna, or carpal bones in addition to ligamentous disruption. The most common of these injuries is the dorsal transscaphoid perilunate fracture dislocation. In contrast, a lesser arc perilunate dislocation is a purely ligamentous injury.^4,5

Patients with a chronic perilunate dislocation may suffer from chronic wrist pain, decreased range of motion, and symptoms of carpal tunnel syndrome.⁶ The literature reports rates of carpal tunnel syndrome at around 50% in patients with acute perilunate dislocation. Unfortunately, a quarter of these are reported to be missed at initial evaluation.^7-9 Mayfield stage IV injuries are most commonly associated with acute carpal tunnel syndrome.¹

Initial management of perilunate injuries generally involves prompt recognition of the injury and closed reduction, if feasible. Standard anteroposterior and lateral radiographs of the wrist are typically sufficient for diagnosis. Immediate recognition of disruption of Gilula’s lines should be identified on radiographs. The reduction maneuver is performed with a reversal of the injury mechanism, with radial deviation, palmar flexion, and intercarpal pronation.¹ Emergent surgical intervention is indicated in the setting of irreducible dislocations. Standard operative management includes open reduction internal fixation of the associated fractures and repair or reconstruction of ligamentous injuries, with or without carpal tunnel release.

Given that up to 25% of perilunate dislocations may be missed at their initial presentation, delayed diagnosis and treatment is not uncommon. In the chronic management of perilunate dislocation, open reduction internal fixation with ligament reconstruction has been described; however, outcomes are significantly worse when performed in chronic or missed injuries.⁸ However, non-operative treatment is not often recommended due to the high risk of recurrent instability and poor functional outcomes.⁸ The literature reports recurring dislocation rates of around 59% in patients treated conservatively.² Reports of patients presenting with chronic injury (more than 6 weeks) with no treatment complain of chronic pain, symptoms of carpal tunnel syndrome, other nerve symptoms, or tendon rupture.^6,10 Salvage procedures, such as proximal row carpectomy or wrist arthrodesis, are thus advocated for in these settings. The success of proximal row carpectomy is dependent on an intact proximal capitate. Therefore, significant trauma to the capitate directs salvage procedure selection toward arthrodesis.

After these injuries, outcomes can be poor, regardless of treatment, especially in higher demand patients or when the dominant arm is affected.⁹ Return of full function, even with surgical treatment is unlikely, with reduced range of motion and grip strength being common.⁹ The authors believe that there is a role for primary proximal row carpectomy as a “salvage surgery” in the acute treatment of PLD/PLFD injuries. We present two patients who were managed with proximal row carpectomy in the acute setting for perilunate dislocation.

Case #1

A 69-year-old right hand dominant male presented after a ground level fall onto his right outstretched hand, sustaining a right perilunate fracture dislocation (image 1). He also presented with median nerve neuropraxia. Successful closed reduction was performed in the Emergency Department (image 2). The patient was diagnosed with a mixed lesser arc-greater arc injury with perilunate ligamentous disruption of the proximal carpal row and fractures of the radial and ulnar styloid. After discussion of management options, the decision was made to proceed with proximal row carpectomy, which was undergone 6 days post-injury. He also underwent carpal tunnel release at the time of the index procedure.

Figure 1A to 1C.

Case #1: Injury XRs (1A), Post reduction XR (1B), Follow up XR (1C)

Figure 2A to 2D.

Case #2: Injury XRs (2A), Post reduction XR (2B), Post-operative XRs (2C), Follow up XRs (2D)

The patient was immobilized in a short arm cast for a total of 6 weeks and transitioned to a removable orthosis thereafter. He had limited access to occupational therapy, and therefore did not complete a formal regimen of postoperative therapy. The numbness to his index, middle, and ring fingers resolved by 6 weeks post-operative. At his final follow up 4 months postoperatively, the patient had intact nerve function, functional range of motion, and no pain. He demonstrated 30˚ wrist extension and 35˚ wrist flexion compared to 55˚ flexion and extension on the contralateral side. His 1-year follow up quickDASH score was 22.7, with main limitations being opening tight jars or heavy household chores where he reported moderate difficulty.

Case #2

A 67-year-old male who was involved in a motorcycle crash, sustaining a right distal radius fracture-dislocation with ipsilateral perilunate dislocation (Moneim type II radiocarpal fracture dislocation). Closed reduction was performed in the Emergency Department. Seven days post-injury, the patient was treated with operative fixation of the distal radius and ulnar styloid and proximal row carpectomy.

Post-operatively, the patient was immobilized for 6 weeks, after which he began range of motion and occupational therapy. At his 5-month follow up, he reported improvement in wrist ROM and pain. On physical exam he was able to achieve 20˚ flexion and 20˚ extension. No sensorimotor insufficiencies were noted. At 3-year follow up, quickDASH score was 27.3, with his primary limitations related to work and recreational activities.

Discussion

Following open reduction and internal fixation of perilunate injuries, patients often continue to suffer from limitations in range of motion (ROM), grip strength and decreased overall function.^9,11,12 This is especially the case in elderly populations, those with severe comminution, those with concurrent injuries, and those who sustained perilunate dislocation or fracture-dislocation injuries to their dominant hand.⁹ Patients may require further surgical intervention to address pain and functional difficulties, such as proximal row carpectomy or arthrodesis.

Forli et al. published a retrospective review in 2010 of 18 patients, average age 34 years (12-63), who suffered either perilunate dislocation or transscaphoid perilunate fracture dislocations treated with ligament reconstruction and operative fixation.¹¹ They achieved follow up of 13 years, assessing Mayo wrist score, ROM, and radiologic evidence of arthritis. Most of their patients did fair or poor, with Mayo wrist scores expressing 3 poor, 7 fair, 3 good, and 5 excellent results. Their reported average flexion-extension at 13 years for perilunate dislocation patients to be 44˚ flexion, 54˚ extension, with grip strength of 75%-87% of their contralateral side. These functional findings were similar to other studies evaluating patients at shorter follow up periods.^13,14 Most patients (67%) demonstrated degenerative changes radiographically, however they concluded the presence of arthritis with static carpal instability did not cause reduced function. The rate of radiographic arthritis was also similar to other studies evaluating patients at 8-year follow up.⁸

In 2016, Griffin et al. published a prospective review of 16 patients, average age of 34 years (15-58 range) with perilunate injuries treated with ligament and fracture repair focusing on PROMs and functional exams.¹² At 24 months, VAS satisfaction score was 7.9 (range 0-10), pain at rest 1.9 (range 0-6), and activity 3.3 (range 1-6). Disability of the arm, shoulder, and hand (DASH) and patient-rated wrist evaluation (PRWE) scores were also reported. The mean DASH score of 25.2 (range 7.5-91.7) and PRWE score of 36.2 (range 14.5-77.3) demonstrated a wide range of patient function, pain, and satisfaction. Mean grip strength was around half compared to the contralateral side (59%), with a mean range of flexion-extension presenting at 71% compared to contralateral wrist. Fourteen of the 16 patients returned to work, 12 returning to the same level of work prior to injury at around 6.4 months (range 3-12 months). Ten of 16 patients returned to sport at an average of 8 months, and 7 were able to return to play at their prior level. While they concluded these patients did overall well, a significant difference compared to contralateral uninjured hand in ROM and grip strength was reported.

In 2018, Dunn et al. reported on outcomes after open reduction and internal fixation (ORIF) of 40 patients who suffered PLD or PLFD in the U.S Military.⁹ Average age of the patient cohort was 28.8 years. While patients reported a decent postoperative ROM of around 74% contralateral side, grip strength lagged to 65% of the contralateral side, and about 78% reported pain with activity. Only 55% remained on active duty at final follow-up of 2 years. The reported complication rate was overall low, with only 7.5% of patients requiring re-operation; one hardware removal and two scaphoidectomies with four-corner fusion. They concluded high-demand patients may expect worse functional results after PLD/PLFD with higher degrees of limitation post op.

While outcomes were not perfect, these studies demonstrate ORIF for PLD/PLFD injuries as a reasonable treatment option in younger patients. While the literature shows ORIF maintains functional ROM and grip strength, PROMs are variable and the risk of requiring subsequent surgery is not negligible. Despite this, it has been shown to be an effective treatment for young patients in long-term follow up studies.

Proximal row carpectomy (PRC) is rarely performed in the acute setting for perilunate dislocations. This is in part due to the relatively successful outcomes with ORIF. However, patients who suffer severe comminution in PLD/PLFD with or without concomitant wrist or hand injuries may benefit from acute PRC as a management strategy to achieve functional ROM and grip strength that has been shown to be equivalent to acute ORIF in certain patients.

Proximal row carpectomy has been shown to be a successful motion-sparing procedure for patients at long-term follow ups. Wall et al. reported on 16 patients, average age 36 years with 20 years follow up after PRC for a variety of conditions. Flexion-extension arcs averaged 68˚, and grip strength 72% of the contralateral side. Eleven (65%) wrists underwent no further surgery, and 10 patients went on to radiocarpal arthrodesis with an average time to conversion of 11 years. They concluded that PRC provided satisfactory results at 20-year follow-up with a survival rate of 65%, and while PRC for younger patients <35 years old may have higher rates of failure, they should not be excluded as PRC candidates.

Chim et al. published a retrospective case series that analyzed success of PRC in patients followed for a minimum of 10 years between 2003 and 2012. The study included 147 patients who underwent PRC for a variety of reasons including arthritis, scaphoid nonunion advanced collapse (SNAC), scaphoid lunate advanced collapse (SLAC), Kienböck disease, rheumatoid arthritis, chronic perilunate dislocation (2 patients), and chronic perilunate fracture dislocation (10 patients). They reported a post operative flexion/extension arc averaging 73.5˚, and grip strength averaging 68.4% of contralateral side. Among studies reporting patient-reported outcome measures (PROMs), they found the average DASH score (weighted mean) was 21.5, PRWE was 28.7, and Mayo wrist score was 66.9 (all scores n=79).¹⁵

While it is difficult to directly compare results of ORIF vs PRC as there is a paucity in the literature of studies describing acute PRC for PLD/PLFD, the general outcomes at long-term follow ups between these two interventions appear to be relatively similar in ROM and grip strength. One study published in 2017 does directly compare ORIF vs PRC in acute treatment of PLD. Muller et al. published a retrospective study to compare the results of ORIF vs PRC in the acute management of perilunate dislocations between 2006 and 2011.¹⁶ The cohort consisted of 21 male patients, average age of 33 years, with isolated or fracture associated PLDs. Thirteen were treated with ORIF and 8 by PRC with no significant differences in age range in each group, and achieved an average follow up of 35 months. They found similar results in pain rating (ORIF 3/10, PRC 1/10), strength (ORIF 77%, PRC 73%), QuickDASH (ORIF 27/100, PRC 16/100), PRWE (ORIF 43/150, PRC 15/5/150), and only slight differences in ROM, with the PRC group demonstrating two-thirds of the motion of the ORIF group. They also found the PRC operative time and immobilization time to be shorter. Thus, they concluded acute treatment of perilunate dislocations by PRC led to medium term results at least as good as ORIF treatment.

The results of these studies and the outcomes of the patients presented above have led the authors to advocate for the use of PRC as the primary treatment of PLD in patients over the age of 65, or those who are low demand. As discussed above, patients undergoing acute PRC vs ORIF for PLD have shown similar ROM and grip strength at long-term follow ups, and similar PROMs. However, Muller found ROM within the PRC patients to be 60% that of the ORIF group.¹⁶ This is concerning when treating young and active patients.

Differences in PROMs at follow-up between elderly or lower-demand patients, and younger or high-demand patients when undergoing PRC also point toward avoiding PRC in younger or more active patients. Ali et al.’s 2012 long-term outcome study of PRC for arthritis found poor patient satisfaction scores, which they attributed to the high percentage of manual laborers within their study, and how they could not return to their prior level of performance.¹⁷ The results of their study led them to become more cautious in offering PRC to young laborers, something that has been reported before by Dacho and others.¹⁸

Revision rates also play a role in the decision of surgical approach, as younger patients (<35 yrs old) treated with PRC showed higher revision rates of 65% at 20-year follow up in Wall et al.’s 2013 paper.¹⁹ Notably, this study did not include ORIF of PLD/PFLD patients as a comparison and thus could not comment on the difference between survival rate of ORIF vs PRC in young patients.

Finally, the length of surgery is also significantly different between PRC and ORIF, with PRC typically taking around 45 minutes in our experience, versus ORIF with ligamentous reconstruction taking 90 minutes or longer. Elderly patients may be less tolerant of the longer surgery and rehabilitation required for ORIF, another reason PRC may be a better choice for this patient demographic. Finally, elderly patients with acute PLD are more likely to have pre-existing degenerative conditions of the wrist. Therefore, initial management with PRC may be the best option for their overall clinical picture.

Conclusion

Though classically considered an option for chronic perilunate dislocations or a salvage procedure in the setting of significant or cartilage and/or bone loss, proximal row carpectomy is a reasonable treatment option for the acute management of perilunate dislocation with satisfactory functional outcomes in older patients, or those with lower activity demand. The cases presented above demonstrate how acute proximal row carpectomy can be utilized in the initial management of complex fracture perilunate type injuries. Ligament reconstruction is often fraught with pain and stiffness post-operatively, to the degree that the motion lost in proximal row carpectomy is essentially equivalent.