Reply to “Letter Regarding ‘Traumatic Nondissociative Carpal Instability: A Case Series’”

Abstract

We would like to thank Drs Lichtman and Pientka1Lichtman D.M. Pientka II, W.F. Letter regarding “Traumatic Nondissociative Carpal Instability: A Case Series”.J Hand Surg Am. 2022; 47: e15Abstract Full Text Full Text PDF Scopus (1) Google Scholar for their interest and commentary regarding our case series.2Loisel F. Orr S. Ross M. Couzens G. Leo A.J. Wolfe S. Traumatic nondissociative carpal instability: a case series.J Hand Surg Am. 2022; 47: 285.e1-285.e11Abstract Full Text Full Text PDF Scopus (3) Google Scholar Debate is always beneficial to the evolution and progress of our specialty. However, we respectfully disagree with the use of the term midcarpal instability to describe this clinical situation, traumatic or not.3Lichtman D.M. Schneider J.R. Swafford A.R. Mack G.R. Ulnar midcarpal instability-clinical and laboratory analysis.J Hand Surg Am. 1981; 6: 515-523Abstract Full Text PDF PubMed Scopus (194) Google Scholar In our opinion, which is shared by Garcia-Elias et al,4Wolfe S.W. Garcia-Elias M. Kitay A. Carpal instability nondissociative.J Am Acad Orthop Surg. 2012; 20: 575-585Crossref PubMed Scopus (32) Google Scholar Wright et al,5Wright T.W. Dobyns J.H. Linscheid R.L. Macksoud W. Siegert J. Carpal instability non-dissociative.J Hand Surg Br. 1994; 19: 763-773Crossref PubMed Scopus (91) Google Scholar and others, the pathology of nondissociative instability concerns both the radiocarpal and the midcarpal joints: it is the proximal row that is unstable, and not the midcarpal joint alone. The injured ligaments responsible for this type of situation cross the radiocarpal and the midcarpal joints. The palliative surgical solutions to counteract this instability each address stabilization of the proximal carpal row, and include radiocarpal solutions (eg, radiolunate fusion, radioscaphocapitate ligament shortening, dorsal radiocarpal ligament plication) and midcarpal solutions (eg, 4-corner arthrodesis).6Garcia-Elias M. The non-dissociative clunking wrist: a personal view.J Hand Surg Eur Vol. 2008; 33: 698-711Crossref PubMed Scopus (42) Google Scholar, 7Johnson R.P. Carrera G.F. Chronic capitolunate instability.J Bone Joint Surg Am. 1986; 68: 1164-1176Crossref PubMed Scopus (70) Google Scholar, 8Ming B.W. Niacaris T. Lichtman D.M. Surgical techniques for the management of midcarpal instability.J Wrist Surg. 2014; 3: 171-174Crossref PubMed Google Scholar, 9von Schroeder H.P. Dorsal wrist plication for midcarpal instability.J Hand Surg Am. 2018; 43: 354-359Abstract Full Text Full Text PDF PubMed Scopus (4) Google Scholar, 10Trumble T. Bour C.J. Smith R.J. Edwards G.S. Intercarpal arthrodesis for static and dynamic volar intercalated segment instability.J Hand Surg Am. 1988; 13: 384-390Abstract Full Text PDF PubMed Scopus (56) Google Scholar, 11Lichtman D.M. Bruckner J.D. Culp R.W. Alexander C.E. Palmar midcarpal instability: results of surgical reconstruction.J Hand Surg Am. 1993; 18: 307-315Abstract Full Text PDF PubMed Scopus (94) Google Scholar, 12Goldfarb C.A. Stern P.J. Kiefhaber T.R. Palmar midcarpal instability: the results of treatment with 4-corner arthrodesis.J Hand Surg Am. 2004; 29: 258-263Abstract Full Text Full Text PDF PubMed Scopus (49) Google Scholar In our opinion, the capitate is not subluxated in volar intercalated segment instability, because the joint remains concentric in all but the most severe cases: it is the entire proximal row that is malrotated.Therefore, we recommend that the terms “carpal instability nondissociative” or “proximal row instability” be used instead of the term midcarpal instability. The pathomechanics of this type of instability are abnormal kinematics of the proximal carpal row because of loss of ligamentous functional integrity, whether congenitally lax or disrupted by trauma. The result is increased static or dynamic sagittal plane rotation between the capitate and the lunate at the midcarpal joint, accompanied by an equal and opposite sagittal rotation of the lunate on the radius at the radiocarpal joint, which reduces with the classic painful catch-up-clunk. This rotation is usually volar, but may also be dorsal or, rarely, both; either way, it involves a dissociation of normal motion of the proximal row, manifested at both the midcarpal and radiocarpal joints.We again thank Drs Lichtman and Pientka for their comments; the objective of our work was to raise awareness of this traumatic carpal instability pattern and encourage early diagnosis and repair of the responsible volar, dorsal, radiocarpal, and/or midcarpal ligaments. We would like to thank Drs Lichtman and Pientka1Lichtman D.M. Pientka II, W.F. Letter regarding “Traumatic Nondissociative Carpal Instability: A Case Series”.J Hand Surg Am. 2022; 47: e15Abstract Full Text Full Text PDF Scopus (1) Google Scholar for their interest and commentary regarding our case series.2Loisel F. Orr S. Ross M. Couzens G. Leo A.J. Wolfe S. Traumatic nondissociative carpal instability: a case series.J Hand Surg Am. 2022; 47: 285.e1-285.e11Abstract Full Text Full Text PDF Scopus (3) Google Scholar Debate is always beneficial to the evolution and progress of our specialty. However, we respectfully disagree with the use of the term midcarpal instability to describe this clinical situation, traumatic or not.3Lichtman D.M. Schneider J.R. Swafford A.R. Mack G.R. Ulnar midcarpal instability-clinical and laboratory analysis.J Hand Surg Am. 1981; 6: 515-523Abstract Full Text PDF PubMed Scopus (194) Google Scholar In our opinion, which is shared by Garcia-Elias et al,4Wolfe S.W. Garcia-Elias M. Kitay A. Carpal instability nondissociative.J Am Acad Orthop Surg. 2012; 20: 575-585Crossref PubMed Scopus (32) Google Scholar Wright et al,5Wright T.W. Dobyns J.H. Linscheid R.L. Macksoud W. Siegert J. Carpal instability non-dissociative.J Hand Surg Br. 1994; 19: 763-773Crossref PubMed Scopus (91) Google Scholar and others, the pathology of nondissociative instability concerns both the radiocarpal and the midcarpal joints: it is the proximal row that is unstable, and not the midcarpal joint alone. The injured ligaments responsible for this type of situation cross the radiocarpal and the midcarpal joints. The palliative surgical solutions to counteract this instability each address stabilization of the proximal carpal row, and include radiocarpal solutions (eg, radiolunate fusion, radioscaphocapitate ligament shortening, dorsal radiocarpal ligament plication) and midcarpal solutions (eg, 4-corner arthrodesis).6Garcia-Elias M. The non-dissociative clunking wrist: a personal view.J Hand Surg Eur Vol. 2008; 33: 698-711Crossref PubMed Scopus (42) Google Scholar, 7Johnson R.P. Carrera G.F. Chronic capitolunate instability.J Bone Joint Surg Am. 1986; 68: 1164-1176Crossref PubMed Scopus (70) Google Scholar, 8Ming B.W. Niacaris T. Lichtman D.M. Surgical techniques for the management of midcarpal instability.J Wrist Surg. 2014; 3: 171-174Crossref PubMed Google Scholar, 9von Schroeder H.P. Dorsal wrist plication for midcarpal instability.J Hand Surg Am. 2018; 43: 354-359Abstract Full Text Full Text PDF PubMed Scopus (4) Google Scholar, 10Trumble T. Bour C.J. Smith R.J. Edwards G.S. Intercarpal arthrodesis for static and dynamic volar intercalated segment instability.J Hand Surg Am. 1988; 13: 384-390Abstract Full Text PDF PubMed Scopus (56) Google Scholar, 11Lichtman D.M. Bruckner J.D. Culp R.W. Alexander C.E. Palmar midcarpal instability: results of surgical reconstruction.J Hand Surg Am. 1993; 18: 307-315Abstract Full Text PDF PubMed Scopus (94) Google Scholar, 12Goldfarb C.A. Stern P.J. Kiefhaber T.R. Palmar midcarpal instability: the results of treatment with 4-corner arthrodesis.J Hand Surg Am. 2004; 29: 258-263Abstract Full Text Full Text PDF PubMed Scopus (49) Google Scholar In our opinion, the capitate is not subluxated in volar intercalated segment instability, because the joint remains concentric in all but the most severe cases: it is the entire proximal row that is malrotated. Therefore, we recommend that the terms “carpal instability nondissociative” or “proximal row instability” be used instead of the term midcarpal instability. The pathomechanics of this type of instability are abnormal kinematics of the proximal carpal row because of loss of ligamentous functional integrity, whether congenitally lax or disrupted by trauma. The result is increased static or dynamic sagittal plane rotation between the capitate and the lunate at the midcarpal joint, accompanied by an equal and opposite sagittal rotation of the lunate on the radius at the radiocarpal joint, which reduces with the classic painful catch-up-clunk. This rotation is usually volar, but may also be dorsal or, rarely, both; either way, it involves a dissociation of normal motion of the proximal row, manifested at both the midcarpal and radiocarpal joints. We again thank Drs Lichtman and Pientka for their comments; the objective of our work was to raise awareness of this traumatic carpal instability pattern and encourage early diagnosis and repair of the responsible volar, dorsal, radiocarpal, and/or midcarpal ligaments. Letter Regarding “Traumatic Nondissociative Carpal Instability: A Case Series”Journal of Hand SurgeryVol. 47Issue 8PreviewWe congratulate Loisel et al1 on their excellent article entitled “Traumatic Nondissociative Carpal Instability: A Case Series.” We applaud their precise description of the surgical pathology and their aggressive repair of the disrupted ligaments. However, we take issue with the term “nondissociative” for categorizing these injuries. Full-Text PDF