NOVEMBER 2015 | Volume 38 • Number 11 n Feature Article abstract Long-term Results After Ankle Syndesmosis Injuries NICOLE VAN VLIJMEN, BSC; KATHARINA DENK, MAPPSC; ALBERT VAN KAMPEN, MD, PHD; RUURD L. JAARSMA, MD, PHD Syndesmotic disruption occurs in more than 10% of ankle fractures. Operative treat- ment with syndesmosis screw fixation has been successfully performed for decades and is considered the gold standard of treatment. Few studies have reported the long- term outcomes of syndesmosis injuries. This study investigated long-term patient- reported, radiographic, and functional outcomes of syndesmosis injuries treated with screw fixation and subsequent timed screw removal. A retrospective cohort study was carried out at a Level I trauma center. The study group included 43 patients who were treated for ankle fractures with associated syndesmotic disruptions between December 2001 and May 2011. The study included case file reviews, self-reported questionnaires, radiologic reviews, and clinical assessments. At 5.1 (±1.76) years after injury, 60% of participants had pain, 26% had degenerative changes, 51% had loss of tibiofibular overlap, and 33% showed medial clear space widening. Retained syndesmotic positions on radiographs were linked to better self-reported outcomes. There is an inversely proportional relation between age at the time of injury and satisfaction with the outcome of the ankle fracture as well as a directly proportional relation between age at the time of injury and pain compared with the preinjury state. Optimal restoration and preservation of the syndesmosis is crucial. Syndes- motic disruption is associated with poor long-term outcomes after ankle fracture. Greater age is a risk factor for chronic pain and dissatisfaction with the outcome of ankle fracture and syndesmosis injury. Therefore, patient education to facilitate real- istic expectations about recovery is vital, especially in older patients. [Orthopedics. 2015; 38(11):e1001-e1006.] The authors are from Radboud University Nijmegen Medical Centre (NvV, AvK), Nijmegen, The Netherlands; and the Department of Orthopaedic Surgery and Acute Trauma (KD, RLJ), Flinders Medi- cal Centre and Flinders University, Bedford Park, South Australia, Australia. The authors have no relevant financial relationships to disclose. Correspondence should be addressed to: Ruurd L. Jaarsma, MD, PhD, Department of Orthopaedic Surgery and Acute Trauma, Flinders Medical Centre and Flinders University, Flinders Dr, Bedford Park 5042, South Australia, Australia ([email protected]). Received: July 11, 2014; Accepted: February 23, 2015. doi: 10.3928/01477447-20151020-09 e1001
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NOVEMBER 2015 | Volume 38 • Number 11
n Feature Article
abstract
Long-term Results After Ankle Syndesmosis InjuriesNicole vaN vlijmeN, BSc; KathariNa DeNK, mappSc; alBert vaN KampeN, mD, phD; ruurD l. jaarSma, mD, phD
Syndesmotic disruption occurs in more than 10% of ankle fractures. Operative treat-ment with syndesmosis screw fixation has been successfully performed for decades and is considered the gold standard of treatment. Few studies have reported the long-term outcomes of syndesmosis injuries. This study investigated long-term patient- reported, radiographic, and functional outcomes of syndesmosis injuries treated with screw fixation and subsequent timed screw removal. A retrospective cohort study was carried out at a Level I trauma center. The study group included 43 patients who were treated for ankle fractures with associated syndesmotic disruptions between December 2001 and May 2011. The study included case file reviews, self-reported questionnaires, radiologic reviews, and clinical assessments. At 5.1 (±1.76) years after injury, 60% of participants had pain, 26% had degenerative changes, 51% had loss of tibiofibular overlap, and 33% showed medial clear space widening. Retained syndesmotic positions on radiographs were linked to better self-reported outcomes. There is an inversely proportional relation between age at the time of injury and satisfaction with the outcome of the ankle fracture as well as a directly proportional relation between age at the time of injury and pain compared with the preinjury state. Optimal restoration and preservation of the syndesmosis is crucial. Syndes-motic disruption is associated with poor long-term outcomes after ankle fracture. Greater age is a risk factor for chronic pain and dissatisfaction with the outcome of ankle fracture and syndesmosis injury. Therefore, patient education to facilitate real-istic expectations about recovery is vital, especially in older patients. [Orthopedics. 2015; 38(11):e1001-e1006.]
The authors are from Radboud University Nijmegen Medical Centre (NvV, AvK), Nijmegen, The Netherlands; and the Department of Orthopaedic Surgery and Acute Trauma (KD, RLJ), Flinders Medi-cal Centre and Flinders University, Bedford Park, South Australia, Australia.
The authors have no relevant financial relationships to disclose.Correspondence should be addressed to: Ruurd L. Jaarsma, MD, PhD, Department of Orthopaedic
Surgery and Acute Trauma, Flinders Medical Centre and Flinders University, Flinders Dr, Bedford Park 5042, South Australia, Australia ([email protected]).
Received: July 11, 2014; Accepted: February 23, 2015.doi: 10.3928/01477447-20151020-09
Ankle fractures are among the most common injuries of the lower limbs.1 Associated disruption of
the syndesmosis occurs in more than 10% of these fractures.1,2 The syndesmotic com-plex tightly connects the distal tibia and fibula to create a firm mortise for articula-tion of the talar dome and tibia. Syndes-mosis injuries involve rupture of 1 or more ankle-stabilizing ligaments. The mecha-nism of injury is hyperdorsiflexion and ex-ternal rotation of the ankle.3 Anatomic re-duction and adequate fixation of the distal tibiofibular joint and syndesmosis are con-sidered essential4 because instability, syn-desmotic widening,5 and talar shift have been linked to poorer functional outcomes and posttraumatic ankle osteoarthritis.6-9 Operative treatment with syndesmosis screw fixation has been successfully per-formed for decades and is considered the gold standard of treatment.10
Only a few studies have reported the long-term outcomes of syndesmosis inju-ries.11,12
Although routine screw removal be-fore weight bearing is common practice, the optimal time for screw removal has not been consistently reported.13 It has been suggested that screw removal ear-lier than 8 weeks postoperatively can lead to loss of anatomic reduction.4 Pos-sible problems associated with failure to remove screws before weight bearing are lack of ankle joint motion (synostosis/osteolysis) and screw loosening or break-age.10 Functional consequences of screw loosening or breakage are controversial.13 The goal of this study was to investigate the long-term outcome of syndesmosis injuries treated with screw fixation and subsequent screw removal. The study also compared the long-term outcome of syndesmosis screw removal within 2 months postoperatively with removal at approximately 3 months.
Materials and Methods This cohort study was conducted at a
Level I trauma center. Before the start of
the study, approval was obtained from the local human research ethics committee.
All patients who were admitted with ankle fractures requiring syndesmosis fix-ation between December 2001 and May 2011 were identified by the hospital cod-ing system. Patients included in the study were treated for any type of distal tibiofib-ular fracture with associated syndesmotic disruption or articular widening; required syndesmosis fixation; were 18 years or older at the time of study follow-up; were able to attend the outpatient clinic for follow-up; and were able to give volun-tary informed consent. Excluded from the study were those who were younger than 18 years at the time of study follow-up; those who were unable to give informed consent; those who were unable to attend the outpatient clinic for follow-up because of large geographic distances; and those who had screw removal that was not com-pleted according to the protocol.
Syndesmotic disruptions were diag-nosed preoperatively by clinical exami-nation and radiographic investigation of tibiofibular overlap and widening of the tibiofibular clear space. Disruption was confirmed intraoperatively with the Hook test.14,15
Syndesmoses were stabilized with 1 or 2 screws, had 3 or 4 cortexes, and were 3.5 or 4.5 mm. This choice of procedure was based on the preference of the surgeon, re-flecting the nature of a university teaching hospital. As is common in large teaching hospitals, ankle and syndesmosis repairs were performed by surgeons with differ-ent levels of training. Syndesmosis screw fixation was done with the ankle in a neu-tral position. After operative fixation, pa-tients were immobilized in a below-knee cast with the ankle in a neutral position without weight bearing for 6 weeks, fol-lowed by weight bearing as tolerated until screw removal.
For participants treated between De-cember 2001 and February 2009, the tim-ing of syndesmosis screw removal had not been specified, and screws were removed
at 2 and 3 months, with most removed 2 months postoperatively. After 2009, screws were left in place for 3 months and removed immediately before full weight bearing. This 2009 change in clinical pro-tocol allowed for comparison of early and late screw removal. Two homogeneous groups were formed.
Eligible patients were invited to attend the outpatient clinic for a final follow-up visit that consisted of functional and ra-diographic assessments as well as self-reported questionnaires. All participants provided voluntary informed consent to take part in the study.
Radiologic Examination Standard anteroposterior, lateral, and
mortise radiographs of the affected ankle were taken at final follow-up for compari-son with previous images. These images were interpreted by a certified radiologist. The goal was to detect changes in syndes-motic width and medial clear space and degenerative changes in tibiofibular joints and joint alignment. Syndesmotic width was determined by measuring the medial clear space and tibiofibular overlap 2 cm15 above the tibia plafond joint line.
Clinical ExaminationThe figure-of-eight method was used
to measure calf and ankle circumfer-ence.16,17 Dorsiflexion, plantar flexion, inversion, and eversion were measured with a goniometer. Inversion and ever-sion were measured in the prone and sit-ting positions without weight bearing. All measurements were compared with the contralateral side.
Subjective OutcomesPatient satisfaction with the outcome
of ankle fracture and syndesmosis injury, pain, and difficulty with activities of daily living were measured with the visual ana-log scale and the Foot and Ankle Outcome Score (FAOS).11,18 The FAOS assesses the patient’s opinion on a variety of problems with the foot and ankle. The score ranges
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from 0 to 500, with higher scores indicat-ing better function. The European Qual-ity of Life-5 Dimensions (EQ-5D) score was used as a standardized instrument to measure health outcome.19-22 Different categories are rated from 1 to 5, with low-er scores indicating better health. Permis-sion to use this score was provided by the EuroQol Group Foundation.
Statistical MethodsFor data analysis, SPSS version 20.0
software (SPSS Inc, Chicago, Illinois) was used. P<.05 was considered statistically significant. Fisher’s exact test was used to compare overall outcomes. Analysis of variance (regression coefficient) was used to investigate the correlation between age and FAOS, EQ-5D, and visual analog scale as well as the correlation between syndes-motic widening and FAOS and EQ-5D.
To assess outcomes after screw re-moval at 2 months (7.9±0.9 weeks) vs 3 months (12.4±0.3 weeks), variables were compared with mean values and propor-tions. Student’s t test was used to compare values between each group to measure statistical significance.
resultsSixty-six patients met the inclusion
criteria for study enrollment. Forty-three attended the orthopedic outpatient clinic for a follow-up visit (Figure 1). Subjec-tive (patient-reported questionnaires), radiographic, and functional long-term outcomes were reviewed. Patient demo-graphics are shown in Table 1.
Analysis of patient-reported question-naires showed that EQ-5D scores were poorest in the category of pain/discom-fort, with 60% (26 of 43) of patients still reporting pain a mean of 5.1 (±1.76) years after injury. In contrast, FAOS results were poorest in the category of quality of life.
Radiographic results after 5 years showed that 26% (11 of 43) of patients had degenerative changes. Fifty-one per-cent (22 of 43) of patients showed some degree of loss of tibiofibular overlap (in-
crease in widening compared with the ini-tial radiograph image). The loss of over-lap was severe (>2 mm increase) in 16 of these 22 cases. Thirty-three percent (14 of 43) of patients showed medial clear space widening.
Clinical examination showed a high incidence of limitation of range of motion in the operated ankle compared with the contralateral ankle (Table 2). Fifty-one percent (22 of 43) of patients had restric-tions in dorsiflexion-plantar flexion, and 58% (25 of 43) of patients had restrictions in inversion-eversion.
A trend in correlations was found be-tween the change in syndesmotic width and the results of self-reported question-naires. Participants with retained syndes-motic reduction scored higher in all FAOS categories except for function, sports
and recreational activities. Likewise, the EQ-5D showed better scores in all catego-ries except mobility when reduction was retained (Figures 2-3).
The effect of age on FAOS, EQ-5D, and visual analog scale scores was in-vestigated. Significant correlations were
Figure 1: Flowchart of enrollment.
Table 1
Patient Demographics and Fracture Classification
Variable Total (n=43)2-Month Group
(n=17)3-Month Group
(n=26)
Follow-up time, mean (SD), y 5.1 (1.76) 6.3 (1.58) 4.4 (1.80)
Age, mean (SD), y 42 (16) 44 (19) 42 (14)
Dislocation, No. 23 10 13
Time until screw removal, mean (SD), wk
10.62 (2.30) 7.88 (0.94) 12.41 (0.30)
Classification, No.
Weber A 3 2 1
Weber B 12 5 7
Weber C 23 8 15
Other 5 2 3
Table 2
Functional Outcome ScoresVariable Mean (SD)
Calf difference, cm 0.0 (1.79)
Ankle difference, cm 1.0 (0.98)
Loss of dorsiflexion-plantar flexion 3.3° (16.8°)
Loss of inversion-eversion 6.4° (16.8°)
Loss of inversion-eversion in prone position 4.2° (14.0°)
found between age and the FAOS catego-ries of function, sports and recreational activities (reflection coefficient [RC]= -0.31; P=.045) and function, daily living
(RC=-0.47; P=.009); the EQ-5D cat-egory of mobility (RC=0.49; P=.001); and the visual analog scale categories of satisfaction (RC=0.64; P=.012) and pain (RC=0.58; P=.004) (Figure 4).
No significant correlations were found between age and radiologic or functional outcomes (P>.05).
Screw breakage occurred in only 2 patients. Both were young men and were treated with 3.5-mm screws that were re-moved 3 months after injury, as per pro-tocol. The effect of syndesmosis screw removal after 2 or 3 months on ankle arthritis and instability was investigated with multiple variables. No relevant sta-tistically significant differences between the 2 groups were found.
Figure 5 shows the radiologic out-come of 2 cases, showing satisfactory vs poor results.
discussionThis study investigated the effect of
syndesmosis injuries associated with ankle fractures on long-term patient- reported, radiographic, and functional outcomes.
When these results were compared with the most comparable normal popula-tion,23 the EQ-5D score showed that the study population had 3 times more prob-lems with mobility and 2.5 times more problems with personal care. The study population also had 2.9 times more prob-lems with usual activities (eg, work, study, housework, family or leisure activities), 2 times more pain/discomfort, and 1.5 times more anxiety/depression than the normal population (Figure 6). Ratings of over-all health did not differ from the normal population. Figures are presented to be comparable to the normal data set.
Figure 2: Regression analysis. Quality of reduction and Foot and Ankle Outcome Score.
Figure 3: Regression analysis. Quality of reduction and European Quality of Life-5 Dimensions.
Figure 4: Regression analysis. Age and outcomes. Abbreviations: EQ-5D, European Quality of Life-5 Dimensions; FAOS, Foot and Ankle Outcome Score; VAS, visual analog scale.
Figure 5: Anteroposterior radiographs showing some widening and osteoarthritis after screw removal over time (A, B) and good outcome at final follow-up (C, D).
A
B
C D
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The demonstrated correlations be-tween syndesmotic width and patient-reported questionnaires have clinical relevance. Accurate syndesmotic reduc-tion and maintenance or improvement of joint position results in better patient-reported outcomes (Figures 2-3). These findings are consistent with previous re-ports,5,12,15,24,25 although they were not statistically significant in the study popu-lation.
Correlations were found between age and various other variables. Some are un-likely to be related to the ankle injury. For example, difficulties with sports and mo-bility are common in elderly people.23,26 However, others must be considered highly relevant. The fact that older people report more difficulties with activities of daily living, more pain compared with the preinjury state, and less satisfaction with the outcome of ankle fracture and syndesmosis injury suggests that greater age is a risk factor for poorer outcomes (Figure 4). To ensure realistic expecta-tions for recovery after syndesmosis fixa-tion, patients should be informed by the surgeon that ongoing problems are to be expected. Screw breakage was very rare in the study population, possibly because of the routine screw removal before full weight bearing. No complications or unfa-vorable outcomes arose from the 2 break-ages reported in the study population. This finding is in keeping with earlier re-ports that showed that retention of loose or broken screws does not lead to worse outcomes.4,27
Consistent with the findings of Hsu et al,13 the current study found no relevant significant differences between screw re-moval at 2 months vs 3 months. Earlier screw removal was not associated with syndesmotic malreduction or poorer func-tional and patient-reported outcomes. Therefore, if screw removal before weight wearing is considered necessary, removal 2 months postoperatively could be con-sidered to prevent the likelihood of pro-longed immobilization and delayed return
to work. The use of more modern tech-niques and devices, such as suture buttons instead of screw fixation, also allows safe early weight bearing and rapid return to work.15,28
LimitationsThis study had some limitations. Op-
erative procedures were performed by surgeons with different levels of training. However, this is a real-life situation that could be anticipated in many other hospi-tals.
Small differences in angles of antero-posterior radiographic images affected the accuracy of measurements and analysis of radiographs. Plain radiographs were somewhat difficult to assess. To ensure accuracy, measurements were taken by 2 researchers independently; means were used. The use of computed tomography could likely improve accuracy. Sagi et al5 recommended routine postoperative bilateral computed tomography scans of syndesmoses, and this study showed con-siderably fewer malreductions and better outcomes after 2 years.
With the number of available partici-pants, statistically significant differences could not be shown between screw remov-al after 2 months vs 3 months. Because of the small sample size, statistical power may not have been strong enough. No post hoc power analysis was conducted because its usefulness is controversial.29,30
conclusionThe study findings showed that syn-
desmotic disruptions can have clear nega-tive effects on long-term functional and overall outcomes after ankle fracture. Most patients reported pain after a mean of 5.1 years. Greater age at the time of injury was a risk factor for chronic pain and dissatisfaction with the outcome of ankle fracture and syndesmosis injury. More accurate syndesmotic reduction and maintenance or improvement of joint position leads to better outcomes. There-fore, optimal restoration and preservation
of the syndesmosis is considered crucial. Outcomes after syndesmosis injuries are frequently worse than predicted, espe-cially in older people. Patient education to facilitate realistic expectations about recovery is vital.
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