Keywords
enchondromas - hand tumors - radiological monitoring - bone augmentation - sole curettage
Introduction
Enchondromas are the most common primary tumors in the small tubular bones of the
hands.[1] They consist of hyaline cartilage and demonstrate slow-growing characteristics.[2] Even though enchondromas are benign tumors, they can compromise the structural integrity
of bone tissue resulting in pathological fractures and further significant damage
to the joints, ligaments, tendons, and neurovascular structures of the hand.[3]
Treatment options for asymptomatic and symptomatic enchondromas without accompanying
fractures are manifold. A large part of cases of hand enchondroma are discovered incidentally
and are asymptomatic.[4] Regular radiological monitoring and conservative management are recommended for
small localized asymptomatic lesions.[4]
[5]
Surgical treatment involves tumor curettage with and without bone grafting.[4]
[6] Various bone graft materials have been described to fill enchondroma-evacuated cavities.[4]
[7]
[8]
[9] However, the use of autologous bone material may be associated with complications
at the donor site, and from a financial perspective, the utilization of other bone
graft materials lacks appeal.[4]
[7] Thereby, adjuvant treatments like high-speed burring or alcohol instillation are
not recommended for enchondroma therapy, because similar outcomes are reached without
additional actions.[4]
[10]
[11]
Different approaches are discussed for pathological fractures. Depending on the presence
of a displaced fracture, a one-stage treatment including curettage and placement of
bone graft or bone block in addition to k-wire osteosynthesis or miniplates could
be done.[12] Alternative option is to allow the fracture to heal first before curettage is performed.[4] Currently, there are no clear data available regarding the extent to which the presence
of a fracture impacts the long-term healing process.
Recurrence rates of enchondromas after complete curettage is reported to be between
6 and 14%.[13]
[14] Malignant transformation seems to be rare, however, cases are described and especially
the entity of chondrosarcoma appears difficult to differentiate.[1]
[9]
[15]
[16]
In this study, we analyzed clinical and radiological outcomes in patients who received
sole curettage for hand enchondroma. We explored the impact of pathological fractures
on these outcomes and the necessity for specialized treatment protocols. The study
compared enchondromas with and without fractures to evaluate treatment efficacy, posttreatment
effects, and the relationship between tumor size and fracture risk. Additionally,
we looked at the incidence of recurrence to see if curettage alone was sufficient
to treat hand enchondroma. Our results were compared with historical data on the use
of bone grafting or other adjuvant therapies.
Methods
The study contains a retrospective data component and a prospective follow-up component.
The inclusion criteria for the study applied to patients with hand enchondroma treated
by sole curettage as identified in our database who were willing to answer questionnaires
or undergo additional clinical and radiological follow-up examinations. The presence
of a pathological fracture resulting from an enchondroma was not an exclusion criterion,
as long as the treatment for the enchondroma consisted solely of curettage. A complete
follow-up must have been completed at least 6 months ago. Patients had to be of legal
age (18 years old) at the time of radiological follow-up. Exclusion criteria were
bone augmentation or other additional treatments after curettage, and contraindications
to radiographic imaging.
Surgical Technique and Treatment Protocol
All surgical procedures were performed by specialists utilizing a dorsal approach.
In instances of non-consolidated fractures, we confirmed fracture healing through
x-rays and physical examination prior to the commencement of surgical intervention.
If bony instability was observed postcurettage, the adjacent joints were immobilized
for a period of 4 to 6 weeks. Following sole curettage, a postoperative regimen was
implemented, ensuring that patients avoided weight-bearing activities for the first
2 weeks. Beyond this initial period, no specific movement restrictions were prescribed.
Data Analysis
From 2000 to 2019, a retrospective study was conducted on all cases of hand enchondroma
treated by sole curettage, confirmed through histological analysis. Patients were
selected using diagnostic codes from our institutional database. Following selection,
patients were contacted via telephone or mail to inquire about their willingness to
participate in the study. Data recorded included gender distribution, age, duration
of surgery, and length of follow-up. Information on follow-up treatments was documented
based on available clinical records. Additionally, tumor size, potential recurrences,
and any complications arising from the treatment were systematically recorded.
Questionnaires and Clinical and Radiological Follow-up
Patients were asked to fill out the DASH questionnaire (Disabilities of the Arm Shoulder
and Hand) and the SF-36 Health Survey (Short Form-36).[17]
[18] In addition, patient-related experience measures were collected by asking patients
about their satisfaction with the treatment both during and after the procedure. Responses
were classified into three categories: “very good,” “good/satisfied,” and “not satisfied.”
During the follow-up study, the patients were called in to have their affected hands
clinically and radiologically examined again. Radiographic examinations were performed
by x-ray images in two perpendicular planes. The observer (H.L., J.K., A.D.) was blinded
to the clinical outcome. The radiological image was inspected for postoperative osteogenesis
and categorized according to the classification of Hasselgren et al. The classification
involved four grades (grade I: excellent new bone formation, grade II: good new bone
formation, grade III: scanty new bone formation, grade IV: no new bone formation).[19]
As part of the physical examination, the sensitivity was assessed by static two-point
discrimination. To objectively assess the operating result, an evaluation scheme quantifying
movement restriction, sensory disturbances, pain, and cosmetic defects was applied,
resulting in grade I (no limitations), grade II (mild limitations), and grade III
(more severe limitations).[20]
Clinical assessment and evaluation of radiological images were performed by senior
physicians. The recurrence rate was recorded by the radiological follow-up examinations
(X-rays) as well as patient history.
Statistical Analysis
Patients presenting with pathological fractures due to hand enchondroma were categorized
into Group I (fracture group), while those without fractures were classified into
Group II (non-fracture group). These groups were analyzed to identify disparities
in clinical and radiological outcomes. Statistical evaluations were conducted using
Matlab R2022b (MathWorks Inc, MA). The normality of data was assessed with the Shapiro–Wilk
test, followed by the application of either parametric or non-parametric tests based
on the results. For normally distributed data, t-tests were employed, whereas the Mann–Whitney U test was utilized for data not following
a normal distribution. A significance threshold was established at p < 0.05 for all statistical tests.
All patients who took part have been informed about the study in conformity with the
Helsinki Declaration of 1975, as revised in 2008. Informed consent was obtained from
all patients prior to inclusion in the study. The regional ethics committee approved
this study under reference number 865/2019BO2.
Results
During the study period, 170 patients underwent surgery for enchondromas of the hand.
A total of 57 patients volunteered to participate in the study and completed all questionnaires
(“fracture group,” group I: n = 28; “non-fracture group,” group II: n = 29). Of those, 43 agreed to participate in clinical and radiological follow-up
(group I: n = 18, group II: n = 25). On average, follow-up for the clinical and radiological follow-up examinations
and answering the questionnaires occurred 7.78 years after surgery, ranging from 2.1
to 18.9 years (mean value group I: 8.67 years; group II: 6.9 years).
In 54.4% (n = 31) enchondromas affected the right hand. Two patients showed polyostotic, but
unilateral tumors (in total, seven polyostotic tumors). None of these two patients
could be classified as having Ollier disease or Maffucci syndrome. While the monostotic
tumors mainly affected the fifth ray (35.1%, n = 20), the polyostotic tumors compromised predominantly the second ray (80%, [Fig. 1]). The proximal phalanx was mainly affected by 42.1% (n = 24).
Fig. 1 Schematic drawing showing the distribution of tumors on the respective phalanges
and metacarpals (left side, number of enchondromas with fractures; right side, number
of enchondromas without fractures).
Three patients had been treated for previous enchondromas in other localizations at
earlier times. In 25 out of 28 cases, fractured enchondromas were caused by minor
trauma (89.3%). The most common symptoms of non-fractured enchondromas (n = 29) were swelling or deformity in the affected area (n = 20/29, 74.1%) followed by pain (n = 7/20, 35%). Two patients were treated with curettage and an additional k-wire osteosynthesis
because of intraoperative instability. No consolidated pathological fracture was noted
at the time of the initial medical presentation. One patient developed a phlegmon
of the dorsal hand after extirpation and required an additional intervention.
Tumor size in ulno–radial and proximal–distal extent did not differ in the groups
of non-fractured enchondromas and fractured enchondromas (p = 0.86). [Table 1] shows a detailed list of the distribution and characteristics such as gender, age,
operating time, and tumor size. A Mann–Whitney U test was used to compare the mean
ages between the two groups, the p-value =0.2 indicates no significant difference in age between the groups. A chi-square
test was used to compare the gender distribution between the two groups with p = 0.91, indicating no significant difference in gender distribution between the groups.
These results confirm that the groups are comparable with respect to age and gender,
validating their equivalence.
Table 1
Patient demographics and evaluation of patients with sole curettage
|
Participants
|
Enchondromas with pathological fractures
|
Enchondromas without pathological fractures
|
Total
|
|
Number of patients, n
|
28
|
29
|
57
|
|
Male/female
|
12 (42.9%)/16 (57.1%)
|
11 (40%)/18 (60%)
|
23 (40.4%)/34 (59.6%)
|
|
Mean age (SD), (years)
|
37.8 (± 12.6)
|
40.9 (± 15.6)
|
39.4 (± 13.7)
|
|
Follow-up (range), (years)
|
8.7 (0.7–18)
|
6.9 (0.3–19)
|
7.8 (0.3–19)
|
|
Operating time (range), (minutes)
|
30.6 (15–76)
|
31.7 (10–72)
|
31.2 (10–187)
|
|
Number of outpatients, n
|
23
|
26
|
49
|
|
Number of inpatients, n
|
5
|
3
|
8
|
|
Hospital stay (range), (days)
|
3.8 (2–7)
|
5 (3–8)
|
4.3 (2–8)
|
|
Suspected recurrence, n
|
0
|
0
|
0
|
|
Proximal–distal tumor size (SD), (mm)
Radial–ulnar tumor size (SD), (mm)
|
15 (± 7.7)
9.5 (± 2.8)
|
15.2 (± 5.7)
10.7 (± 3.2)
|
15.1 (± 7)
10.2 (± 2.9)
|
Abbreviation: SD, standard deviation.
DASH and SF-36 Health Questionnaire
All 57 patients had completed the DASH and SF-36 health questionnaires ([Figs. 2] and [3]). The results of the DASH questionnaire showed a low impairment score for both groups.
There were no significant differences between the groups (p = 0.58). The SF-36 health questionnaire also showed no significant difference between
the fracture and non-fracture groups regarding their physical (p = 0.47) and mental composite scores (p = 0.89). Moreover, both groups showed no significant differences compared to the
healthy population and have returned to normal quality of life (fracture group: p = 0.77; non-fracture group: p = 0.69).
Fig. 2 The DASH score for assessing upper extremity functionality including outliers and
median, displayed for both groups (fracture group: 3 [±5.6]; non-fracture group: 5
[±7.3]). DASH, Disabilities of the Arm Shoulder and Hand.
Fig. 3 Normalized SF-36 subscale scores of enchondroma patients that presented with a fracture
(left) or non-fracture (right) compared to the scores of the general healthy population
(orange line, PF, physical functioning; RP, role physical; BP, bodily pain; GH, General
Health; VT, vitality, SF, Social Functioning; RE, role-emotional; MH, mental health;
PCS, Physical Composite Score; MCS, Mental Composite Score). SD, standard deviation;
SF-36, Short Form-36 Health Survey.
Subjective Perception during Operative Treatment and Postoperative Course
According to the patient-related experience measures, 49 patients reported being very
satisfied with the treatment, and outcomes were reported to be very good at 86% (49/57).
Seven participants were moderately satisfied (8.1%).
Patients for Clinical and Radiological Examinations
Forty-three patients agreed in clinical and radiological follow-up examinations (75.4%;
n = 43/57). Of these, 18 participants belonged to the fractured group (enchondromas
with pathological fractures, 41.9%, female n = 10/male n = 8) and 25 participants to the non-fractured group (enchondromas without pathological
fractures, 58.1%, female n = 15/male n = 10, [Fig. 4]). In total, 74.4% (n = 32/43) of the patients had mild or no limitations in the criteria “Pain,” “Movement
restrictions,” “Sensory disturbances,” and “Cosmetic defects” during the clinical
examination. Twelve patients had more severe limitations (27.9%, [Table 2]). Of these 12 patients, 10 reported a difference in sensitivity compared to non-treated
areas. Static two-point discrimination was in a normal range of 4.59 mm on average
(± 2.1 mm). Complete loss of sensation or neuroma-associated symptoms did not occur.
Three patients showed limitations of flexion in the adjacent finger joints (7%, n = 3/43). Four patients had measurable minor axis deviation to the opposite side (9.3%,
4/43). No significant difference could be found between both groups (p = 0.39).
Fig. 4 (a, b) show the radiographs of a patient before and 6 years after curettage due to a non-fractured
enchondroma at the distal phalanx of the little finger. (c) shows the X-ray image of another patient with a pathological fracture due to an
enchondroma on the proximal phalanx of the ring finger. In this case, fracture healing
was initially awaited. The enchondroma can be clearly demarcated after the fracture
has healed (d).
Table 2
Clinical assessment by evaluating the criteria “pain,” “movement restrictions,” “sensory
disturbances,” and “cosmetic defects”
|
|
Enchondromas with pathological fractures, n
|
Enchondromas without pathological fractures, n
|
|
Grade I
|
No limitations
|
5 (27.8%)
|
6 (24%)
|
|
Grade II
|
Mild limitations
|
9 (50%)
|
11 (44%)
|
|
Grade III
|
More severe limitations
|
4 (22.2%)
|
8 (32%)
|
Radiological Results
Results of new bone formation are shown in [Table 3]. Both groups displayed excellent and good new bone formation. The groups did not
show any significant differences in outcomes (p = 0.92). Bony healing was confirmed in all cases, and neither recurrences nor malignant
transformations were identified during the radiological reevaluations.
Table 3
Evaluation of radiographic imaging
|
|
Enchondromas with pathological fractures, n
|
Enchondromas without pathological fractures, n
|
|
Grade I
|
Excellent new bone formation in the cavity and normal cortical thickness
|
10 (55.6%)
|
14 (56%)
|
|
Grade II
|
Good new bone formation in the cavity and/or cysts <3 mm present
|
6 (33.3%)
|
7 (28%)
|
|
Grade III
|
Scanty new bone formation in the cavity and/or cysts >3 mm present
|
2 (11.1%)
|
4 (16%)
|
|
Grade IV
|
No new bone formation in the cavity
|
0
|
0
|
Discussion
This study offers insights into the long-term outcomes of treating enchondromas with
sole curettage by collecting data through patient questionnaires and conducting clinical
and radiological follow-ups. The generally favorable results suggest that it is worth
considering additional interventions, such as bone augmentation, for further discussion.
The present study is the largest report to date of long-term radiological and clinical
follow-up of patients treated for hand enchondromas by curettage alone. Radiographic
follow-up was performed for over 7 years and no evidence of suspected recurrence was
observed. Although this study did not include interindividual comparison in our study,
its findings are consistent with other studies that suggest that curettage alone does
not lead to worse long-term outcomes.[6]
[10]
[21]
The technique of sole curettage for hand chondromas has been well-documented.[19]
[22] However, additional bone augmentation is often deemed appropriate, particularly
for large or expanding tumors.[9] In a study focusing on the metacarpus, Pianta et al illustrated that calcium phosphate
bone cement enhanced strength compared to curettage alone in a cadaveric model of
hand enchondroma. Nonetheless, they noted that in clinical practice, this added strength
might not offer significant benefits.[23] Although artificial bone substitutes, including bioactive and osteoconductive materials
in various forms, provide advantages such as reduced donor site morbidity and shorter
operating times, their treatment cost is considerably higher compared to alternative
options.[8]
[9]
[24] Autologous bone grafting is often considered the optimal choice due to factors such
as avoidance of immune rejection, cost-effectiveness, and ready availability through
access to the dorsal radius or pelvic region. However, there are two major concerns
regarding bone augmentation. Firstly, the complication rate associated with the donor
site in autologous bone transfer can be significant. For example, caution is advised
when using iliac crest autografts for augmentation, as they may result in pain and
infection at the donor site.[4] The main complications of distal radius bone grafting are pain, tenosynovitis, infection,
fracture, and nerve injury.[25] Secondly, recurrence risk in solitary enchondromas does not appear to be positively
affected by augmentation,[21]
[22]
[26] as recurrence is most likely caused by incomplete curettage. Due to the slow growth
rates of these tumors, it can be challenging to detect suspected recurrences, and
additive bone grafting does not improve outcomes after surgical therapy for solitary
enchondroma in the hand.[6]
[22]
[26]
In our opinion, autologous bone grafting continues to play a significant role in the
treatment of enchondromas. During the study period at our center, 6.5% of all patients
with enchondromas (11 out of 170) presented with a massive cortical defect and intraoperative
instability. Due to the severity of these defects, these patients were treated with
autologous bone grafts harvested from the iliac crest. Of these patients, eight underwent
additional osteosynthesis or arthrodesis procedures. Six patients reported experiencing
pain at the donor site for several weeks; however, this discomfort resolved by the
seventh postoperative week at the latest. All patients demonstrated successful consolidation
and expressed general satisfaction with their outcomes. It is important to note that
long-term results remain undetermined due to these patients not being part of the
inclusion criteria.
Consistent with findings from other studies, our study population predominantly exhibited
diagnosis establishment in the fourth decade of life, with no gender specificity.[27] Enchondromas were most localized at the proximal and ulnar parts of the phalanx,
aligning with existing literature.[27] Within our study, two patients presented with polyostotic tumors. In both cases,
the tumors affected only one hand unilaterally, with no other tumors detected, suggesting
a possible diagnosis of Ollier disease, also known as multiple cartilaginous enchondromatosis.
While malignant transformation of one or more enchondromas towards secondary central
chondrosarcoma is possible, such transformations typically affect enchondromas of
long tubular and flat bones, with the risk of malignant transformation in hand enchondromas
being low.[28] Notably, these two patients exhibited no changes in tumor deformity and experienced
no recurrence following sole curettage.
Most enchondromas were diagnosed because of symptoms and complaints such as swelling,
impaired hand function, and/or pain in the affected area. In our patient cohort, 93%
of those with non-fractured tumors presented with these symptoms. Pathological fractures
are commonly feared during the progression of the disease and occur in up to two-thirds
of patients.[29] Because of the bone's weakened state, even minor trauma can result in fracture.
In our patient cohort, approximately half experienced fractures, with the majority
of cases attributed to minor traumas (89.3%). These observations align with findings
reported in the literature.[14]
Riester et al tried to identify objective and reproducible criteria that predict a
patient's risk of developing a pathological fracture due to an enchondroma.[3] They determined that younger age, smaller finger size, localization in the distal
and proximal phalanx, and particularly the percentage of bone occupied by the tumor
in the longitudinal dimension are correlated with a greater risk of developing fractures.[3] In our study, we did not observe a difference in tumor size between fractured and
non-fractured enchondromas. While the concept of greater loss of bone integrity leading
to increased fracture risk seems reasonable, cortical thinning appears to be more
plausible for pathological fractures.[3] However, in our study, pathological fractures caused by enchondromas were permitted
to heal before curettage was performed. Only two patients underwent treatment with
k-wire osteosynthesis due to intraoperative instability resulting from curettage.
The overall outcome of surgical treatment for fractured enchondromas is expected to
be largely favorable, with outcomes typically ranging from good to very good and rare
complications, similar to those observed in non-fractured enchondromas.[12] In a systematic review by Tang et al of mainly level IV studies, complication rates
ranged from 0 to 3.5%.[4] Regardless, significant malalignment should be corrected promptly. If the fracture
necessitates an open approach, immediate treatment of the enchondroma should be considered.[30] Some authors prefer bone augmentation in fractured enchondromas, as they consider
cortical thinning due to curettage a risk to subsequent bone healing.[24] However, there are currently no long-term results that have been radiologically
verified. In our study, patients were followed up for 7 years, and the use of curettage
alone did not result in worse outcomes in terms of bone healing and clinical outcomes
for fractured enchondromas.
Within the scope of this study, patients reported high satisfaction following surgical
treatment, which corresponded with their perception of upper extremity health status
and function. Both groups exhibited a median DASH questionnaire score below 6, indicating
high self-reported functionality in hand and finger movements ([Table 1] and [Fig. 2]). This suggests that patients were capable of performing most daily activities without
notable difficulty or impairment. These results align with those of the SF-36 questionnaire,
which revealed no significant differences from a healthy norm population.
A conservative approach as an alternative treatment demonstrated a significantly better
functional outcome in comparison to operative procedures, as shown by a larger study
investigating the outcome of enchondromas and atypical cartilaginous tumors of the
long bones.[31] The generalizability of these findings to enchondromas of the hand is uncertain
and may be subject to questioning. It is undeniable that the indication for operative
treatment of enchondromas is given if specific symptoms are present.[20] In case of a non-symptomatic enchondroma and small extension as well as lacking
signs of cortical damage clinical follow-up examinations are justifiable.
This study has some limitations. Firstly, the patient population did not receive alternative
treatment options such as bone augmentation, which limited these comparisons to existing
literature. The use of bone augmentation is of relevance, especially in cases of defects
with extensive cortical destruction. However, despite this limitation, the study revealed
a low complication rate and generally favorable to very favorable outcomes, even in
cases involving larger hand enchondromas with no observed recurrences. Secondly, the
study design permitted only a single assessment of clinical and radiological outcomes
years after surgery, and a quarter of the patients declined clinical and radiological
follow-up examinations. Moreover, these assessments were not conducted at strictly
defined intervals postoperation, except for a requirement of at least 6 months. Therefore,
patient-perceived insight into the immediate postoperative course was limited and
the comparison between the two groups must be viewed critically. Due to the extended
follow-up period, there may be a bias in the patient's personal perception of their
outcomes. However, it can be stated that patients with pathological fractures due
to hand enchondromas do not have to expect a more complicated healing process.
Conclusion
Sole curettage demonstrates a low rate of complications and is generally well-accepted
as a treatment for hand enchondromas. Recurrence is rare, and patient satisfaction
is high. Our study indicated that the presence of pathological fractures did not impact
long-term outcomes. Curettage alone proves to be adequate as a therapy for enchondromas,
even in cases of pathological fractures. However, it is advisable to allow fracture
healing to occur first. In the case of extensive cortical destruction, cancellous
bone surgery should nevertheless be discussed as an additional therapeutic procedure.
