Copyright 1984 by The Journal of Bone and Joint Surgery bworporated

The Natural History of Scaphoid Non-Union*BY COMMANDER GREGORY R. MACK’S, MEDICAL CORPS, UNITED STATES NAVAL RESERVE,

LIEUTENANT COMMANDER MICHAEL J. BOSSE~’, MEDICAL CORPS, UNITED STATES NAVY,

RICHARD H. GELBERMAN, M.D..~, AND ERIC YU, M.D.§, SAN DIEGO, CALIFORNIA

From the Naval Regional Medical Center and the Universi O, of California at San Diego. San Diego

ABSTRACT: We reviewed the clinical and roentgen-ographic findings of forty-seven non-unions of a fractureof the scaphoid in forty-six symptomatic patients in orderto assess the incidence and severity of degenerativechanges of the wrist. The duration of non-union rangedfrom five to fifty-three years. Three roentgenographiicpatterns were seen: twenty-three lesions had sclerosis,

¯ cyst formation, or resorptive changes confined to thtescaphoid bone (Group I); fourteen had radioscaphoidarthritis (Group II); and ten had generalized arthritiisof the wrist (Group III). The duration of Group-I non-unions averaged 8.2 years; Group-II, 17.0 years; andGroup-III non-unions, 31.6 years. Fracture displace-ment and carpal instability correlated with the severityof degenerative changes. Lunate dorsiflexion of 10 de-grees or more was a useful guide to carpal instability’.Few of the forty-seven non-unions were undisplaced,stable, or free of arthritis after ten years. Based on thehigh probability of arthritis, we recommend that all dis-placed ununited scaphoid fractures he reduced andgrafted, regardless of symptoms, before degenerativechanges occur. Asymptomatic patients with an undis-placed, stable non-union should be advised of the 0os-sibi.lity of late degenerative changes.

Scaphoid nonunion occurs in approximately 5 per centoftreated scaphoid fractures9.14 and in an unknown numberof unrecognized fractures. Although much has been writtenabout the cause2’9,l°A2’~4,25,3z,3’~.36 and treatment~.~-7,t~.~3.~5,~:’-24.26,29-31,33.34 of non-union, and while several authors haw~

stated that non-union leads to degenerative arthritis, thenatural history of the ununited scaphoid fracture is notknown. In a review of the cases of forty-six symptomatic.patients with ununited scaphoid fractures (forty-seven non.-unions) of five to fifty-three years’ duration, we tried toidentify the patterns and prognostic indicators of degener..ative arthritis.

* The opinions and assertions expressed herein are those of the authorsand do not necessarily reflect those of the Bureau-of Medicine and Surgeryor the Naval Service at large.

? Department of Orthopaedics, Naval Hospital at San Diego, SanDiego, California 92134. Please address reprint requests to CommanderMack.

~ Division of Orthopaedics and Rehabilitation, University of Cali-fornia at San Diego, 225 Dickinson Street, San Diego, California 92103.

§ 450 Sutter Street, San Francisco, California 94108.

Material and Methods

- All of the records of patients who were evanon-union of the scaphoid at the Naval RegionalCenter and the University of California at San DiL1972 to 1982 were retrieved. The criteria for inclthe study were a scaphoid non-union of at leastduration, and personal examination by one of us orthat included complete historical and rangsurements. Patients with prior surgical treatmentcluded. Only patients with symptomatic non-unio~i!iincluded. New roentgenograms of the wrist werethe time of the most recent examination. Sixty-fourwere identified. Sixteen patients who could not bewere excluded because roentgenograms were noavailable to us. Thirty-four patients were examinedof us. Two were excluded because ofinjuries: one, a displaced fracture of the radialthe other, an unreduced trans-scaphoiddislocation. Adequate records and roentgenogramswere available for forty-six patients withphoid non-unions. Twenty-eight patients werethe military, including sixteen who were on a_cJivetwelve who had retired from military service.

Thirteen of the patients had sustained theprior to entry into the Navy. On careful questioning,ever, all admitted having had symptoms at thelistment which became wdrse on active duty.had bilateral non-union, but the opposite wrist of onewas excluded from the study because oftreatment. In thirty-five patients the dominantinvolved.

Only two patients were women, but thisreflect the fact that the population of the militarypredominantly male.

The roentgenograms includedand oblique projections of the wrist andlocation and configuration were determined asRussez~. Non-unions with cortical offset of oneor more on any roentgenogram were consideredInstability was determined by measuring theangle on the lateral roentgenogram; an angle of more70 degrees was considered abnormaP6. Because thiswas often obscured by degenerative change,and angulation of the fracture, dorsiflexion of the

THE NATURAL HISTORY OF SCAPHOID NON-UNION 5O5

used to determine carpal instability. This was mea-which is determined by mea-

amount of lunate dorsiflexion with respect to theaxis of the radius (Fig. l-A). The normal valueis 7 degrees of palmar flexion when the wrist

position (average range, 12 degrees of palmar9 degrees of dorsiflexion)27. In this study, 10

’lunate dorsiflexion or more was considered ab-

the amount of carpal collapse and radialof the distal carpal row, the carpal height ratio-ulnar distance ratio were determined as describedet al. 36. Abnormal values were a carpal height

L50 or less (normal value, 0.54 ___ 0.03) and ~,~stance ratio of 0.34 or more (normal value,

(Fig. 2).established, based

of the degenerative changes. Group-I lesionsof the fracture margins, cyst formation, or

changes confined to the scaphoid (Figs. 3-A andlesions showed radioscaphoid arthritis, in-

i joint-space narrowing or pointing of the radial sty-both (Figs. 4-A and 4-B). Patients with a Group-

III lesion had advanced generalized arthritis of the wrist(Figs. 5-A and 5-B).

For each roentgenographic group, we determined theaverage duration of the non-union and the incidence of ab-normal roentgenographic findings (displacement, radiolu-nate angle, scapholunate angle, carpal height ratio, andcarpal-ulnar distance ratio). Each of these specific roent-genographic findings was also correlated with the durationof the non-union.

The symptoms were classified as mild, moderate, orsevere. Patients with mild symptoms had pain only withstrenuous use of the wrist and rarely required medication.Patients with moderate symptoms frequently had pain that:required rest and medication. Patients with severe symptomshad pain at rest, took pain medication regularly, and avoidedmanual work and sports requiring motion of the wrist.

Results

Roe, ntgenographic analysis showed progressive degen-erative changes with time. At between five and ten yearsalmost all non-unions showed cyst formation and resorptivechanges within the scaphoid. Degenerative arthritis of theradioscaphoid joint was most common after ten years. Gen-

FIG. 1-A

The longitudinal axis of the. radius (R) and horizontal axis of the lunate (L) determine the radiolunate angle (RLA).

FIG, 1-BDorsiflexion instability with a radiolunate angle of 30 degrees. Note that the third metacarpal is parallel to the radius.

5O6

eralized arthritis of the wrist occurred frequently after twentyyears of follow-up.

G. R. MACK, M. J. BOSSE, R. H. GELBERMAN~ AND ERIC YU

FIG. 2The carpal height ratio is the ratio of the carpal height (B) to the height

of the third metacarpal (A). The carpal-ulnar distance ratio equals thedistance (C) from the center of rotation of the capitate to the projectedlongitudinal axis of the ulna, divided by the height of the third metacart~al(A)~

Twenty-three non-unions were in roentGroup I; fourteen, in Group II; and ten, inwas a strong correlation between the severity of dechanges and the duration of non-union. Group-Iaveraged 8.2 years in duration; Group-II, 17.0Group-III non-unions, 31.6 years. The averagethe lesions was 15.9 years. The difference w2s si

between Groups I and II (p < 0.005) and betweenI and III (p < 0.001). The majority of the non-u~less than ten years’ duration were in Group I, wheof the non-unions of more than twenty years’ durin Group III.

TABLE I

POSITIVE ROENTGENOGRAPHIC FINDINGS

IN THE ROENTGENOGRAPHIC GROUPS

Group I Group II

Total no. 23 14No. displaced 9 14Radiolunate angle 8 14

~> 10 degrees

Scapholunate angle 8 14>70 degrees

Carpal height ratio 2 6~<0.50

Carpal-ulnar distance 2 5ratio ~>0.34

Progressive degenerative changes alsowith displacement, the radiolunate and scapholunate~and the carpal height ratios (Table I). Only ninethree Group-I lesions had a displaced non-unionall patients in Groups II and III had a displacedThe radiolunate and scapholunate angles bothmal in only eight of twenty-three wrists in Groupared with all of the wrists in Groups II andradiolunate angle was greater in Groups II and III10.15 and 23.9 __ 9.79 degrees, respectively) than I (8.2 __ 12.15 degrees). These differencessignificant (p < 0.001)../

FIG. 3-A FIG. 3-BFig. 3-A: In Group I, non-unions demonstrated cystic, resorptive changes or sclerosis at the fracture margins.Fig. 3-B: A Group-I scaphoid non-union with cystic resorption. Note the absence of degenerative changes in the radioscaphoid joint.

THE NATURAL HISTORY OF SCAPHOID NON-UNION 507

Fro. 4-A FIG. 4-B

Group-II non-unions are characterized by degenerative changes in the radioscaphoid joint.,4-B: Note the pointing of the radial styloid. The distal fragment is displaced and appears on this roentgenogram to abut the styloid.

angle correlated with the scapholunate.-,ire of forty-seven wrists and correlated with

m forty-one of forty-five. The average radio-was 2.6 _ 7.45 degrees in undisplaced non-

with 21.6 _+ 11.04 degrees in displaced(p < 0.001).

height ratio was decreased in two patientssix in Group II, and seven in Group III (Table

a significant difference in this ratio betweenIII (p < 0.005) and between Groups II and

Twelve patients had an abnormal carpal-ulnar distanceratio. Five were in Group II and five, in Group Ill. Therewas a significant difference between the mean ratios ofGroups I and II (p < 0.05) and those of Groups I and III(p <: 0.01).

Fracture location and configuration did not correlatewith degenerative changes or other roentgenographicfindings.

Th.~" duration of non-union was five to nine years fortwenty-two lesions, ten to nineteen years for nine, andtwenty years or more for sixteen. Before ten years, only

FIG. 5-A FtG. 5-B

l ’-?,, on-umons are characterized by degenerauve arthrms throughout the wrist.n z~:a-:’:~,ion to generalized arthritis there is radial migration of the distal carpal row. Apparent carpal collapse was not significant in thiscarpal collapse or radial shift of the distal row, or both, were found in more than half the Group-III wrists.

508 G.R. MACK, M. J. BOSSE, R.

half of the non-unions showed additional roentgenograph:icabnormality. After ten years, however, more than 88 percent of all of the non-unions were displaced and unstable.There was also a trend for carpal collapse (carpal heightratio of 0.50 or less) and radial migration of the distal carpalrow (carpal-ulnar distance ratio of 0.34 or more) to be morecommon with increasing duration of non-union (Table II).

TABLE II

PERCENTAGE OF ABNORMAL ROENTGENOGRAPHIC FINDINGSCORRELATED WITH DURATION OF NoN-UNION

5 to 9 Yrs. 10 to 19 Yrs. 20 Yrs. or More

Total no. 22 9 16Displacement 50% 89% 94%Radiolunate angle 41% 89% 88%

~ 10 degreesScapholunate angle 41% 89% 88%

>70 degrees

Carpal height ratio 18% 33% 50%40.50

Carpal-ulnar distance 18% 22% 50%ratio ~>0.34

Thirty-five patients had mild or moderate symptoms.In these patients, no correlation was seen between the syrup-.toms and the roentgenographic findings or the duration ofthe non-union. Eleven patients had had severe symptoms.for six months to six years. All had a displaced non-union,and ten had instability of the wrist (a radiolunate angle of10 degrees or more and a scapholunate angle of more than70 degrees)i

Thirteen patients attributed their symptoms to a recent-.injury. There was no significant difference, however, in thepercentage of patients with mild, moderate, or severe symp-toms in the group of patients with a reinjury and the groupthat attributed the symptoms to the original injury. For bothgroups, the average age of the fracture when the patientswere referred to us was sixteen years.

Discussion

The natural history of scaphoid non-union and the in-cidence of subsequent arthritis have not been clearly estab-lished. Dickison and Shannon found arthritic changes in 30per cent of seventy late fractures, but did not specify theage of those injuries~. London reported on sixty non-unions,with degenerative arthritis in thirty-six, and observed thatthe severity of arthritis increased with time17. Twenty-fiveof the lesions in his series, however, were of unknownduration.

The present study was designed to determine the naturalhistory of the scaphoid non-union. The findings were lim-ited, however, to patients who were seen for evaluation ofa symptomatic non-union. A prospective longitudinal studyof individual patients"\would be required to determine ifdegenerative arthritis al~so occurs in asymptomatic patientswith a scaphoid non-union. It is possible, for example, thatan undisplaced non-union in a sedentary patient is less likely

H, GELBERMAN, AND ERIC YU

to displace, slower to undergo degenerative chanless likely to cause symptoms that our data suggest.we found the statistical incidence of displacementgenerative change to increase so greatly after tenhowever, we would expect the effect of this bias to be

The data in this study suggest that manysymptomatic scaphoid non-unions undergo aquence of degenerative changes, and that arthritis is 1to occur if sufficient time elapses after the non-univelops. Cyst formation, radioscaphoid arthritis,eralized arthritis of the wrist -- hallmarks of theseen in Groups I, II, and III -- occurred in thedecades after injury. In the first decade, all but onehad cystic resorptive changes within the scaphoid, and ~quarters showed only Group-I changes. Further det(appeared to occur in the second decade in mostAfter nineteen years, radioscaphoid arthritis wasall but one patient. Extensive arthritis of the wristdeveloped, and by thirty years severe changes werein all of the wrists. It thus appears that few symwrists can be expected to be free of degenerativefor more than a decade after injury, and most willestablished arthritis by twenty years.

The most significant factors associated withwere displacement of the fracture and instabilit~Both were present in more than 90 per cent of thewith Group-II or III changes in our series. Thisdicted by Fisk~°, who thought that instabilityof non-union and early degenerative change.that instability was due to perilunar ligament damathe original injury. In our series, however, thenon-unions in Group I, and less than ten years old,show these findings. Becauseinstability, and degenerative change is so high init appears that not only does displacement lead toerative change, but also that displacement and inscan occur as late phenomena in ~unions.

Because displacement a~nd instability correlatejwith arthritis, we would expect that in untreatedthat are initially displaced arthritis will developthan the data in this series indicate. We could notstatistically due to the retrospective naturebecause only old injuries were included. Prodegenerative change may also be underestimatedthe age of the non-union in most patients wasgreater than the time at which the observedcurred.

In scaphoid non-unions, lunate dorsiflexion isguide to fracture displacement and carpalgenerally been agreed that displaced injuries arestable5"6"19. Displacement may be obscured,degenerative changes. Instability is usually measured on.lateral roentgenogram by means of the scapholunatewhich is increased by lunate dorsiflexion and palmarof the scaphoid. In scaphoid fractures, however,or displacement of the fragments disrupts the

:ive changesuggest.acement and!after tenbias to bemany

’,o a

arthritis is 1.e non-unthritis, ands of thein the1 but one)hoid,,andher deterrl mosts was~ the wristges were~wnerativest will have

.~d withilit]t of the¯ This was:y was the.~. Hetat damagethe "

:ars old,

;h in laterlead toand

ndisplaced:

Teatedopd not showf ourojectedimated¯ was

~ion is a u~,stability.iuries

leasured on 1

palmarvt~r,

THE NATURAL HISTORY

In a scaphoid non-union, degenerativefurther obscure the scaphoid outline2 In our ex-the lunate silhouette is easily visualized on a true

roentgenogram, even in the presence of degenerativeFor these reasons we prefer to measure both the

angle and the scapholunate angle to assess theit)’ in a scaphoid non-union. Sarrafian et al. deter-the normal range of the radiolunate angle to be - 12degrees when the third metacarpal is parallel to the

the absence of extension of the wrist and ulnar de-which increase lunate dorsiflexion, higher values

seen in normal wrists. In our study, use of theangle to assess instability is supported by its

OF SCAPHOID NON-UNION 509

correlation with the scapholunate angle and displacementof the fracture. When displacement and instability do notcorrelate it may be helpful to make roentgenograms of theopposite wrist for comparison.

Based on the high probability that degenerative changeswill occur, we recommend that a scaphoid non-union thatdemonstrates displacement and instability be reduced andgrafted before degenerative changes occur. An asympto-mati.c patient with an undisplaced non-union and no evi-dence of instability of the wrist should be advised of thepossibility of late degenerative changes.

NOTE: The authors wish to thank Marilynn Wyatt, M.A., R.P.T., of Children’s Hospital andHealth Center, San Diego, California, for providing assistance with the statistical analysis in thisstudy.

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