Keywords
endoscopic diskectomy - percutaneous endoscopic lumbar diskectomy - microendoscopic
diskectomy - athletes - return to play
Introduction
Athletes present unique injury risk factors and care considerations for spinal disorders.
Among elite athletes, low back pain has a considerable impact on playing time.[1] Furthermore, participation in competitive athletics may be associated with increased
risk of degenerative disk disease and lumbar disk herniation caused by microtrauma
and chronic pressure on the spine without adequate time to heal.[2]
[3] Management of symptomatic disk herniation in athletes involves return to play evaluations
on an individual basis with consideration of the patient's type of sport and position.[4] In a systematic review of elite athletes with lumbar disk herniation, return to
play rates varied and depended on the type of sport played. Major League Baseball
(MLB) players had the greatest return to play rate, while National Football League
(NFL) players had the lowest return to play rate.[5] Interestingly, there was no significant difference in return to play outcomes in
patients who were treated conservatively and patients who underwent diskectomy; however,
patients in the NFL who underwent diskectomy had a longer postoperative career length
compared to patients who received conservative treatment. The opposite was true for
patients in the MLB.[5]
A systematic review regarding return to play rate in athletes following traditional
lumbar diskectomy reported return to play rates ranging from 75 to 100%.[6] Average time to return to play ranged from 2.8 to 8.7 months.[6] Postoperative performance depended on the athlete's chosen sport, with hockey players
experiencing the greatest decline in performance, while football players experienced
a slight performance improvement.[6] Regardless, there is a place for lumbar diskectomy in the management of lumbar disk
herniation in elite athletes.
Although studies have been performed regarding traditional diskectomy in athletes,
there is little evidence regarding endoscopic approaches in athletes. Percutaneous
endoscopic lumbar diskectomy (PELD) and microendoscopic diskectomy (MED) have been
shown to have no difference in postoperative visual analog scale (VAS) and Oswestry
Disability Index (ODI) scores with decreased postoperative length of stay and return
to work time compared to traditional open diskectomy in the general population.[7]
[8]
[9]
[10]
[11] PELD refers to a 6- to 7-mm diameter cannula, inserted percutaneously under fluoroscopic
guidance through either the transforaminal or interlaminar space to access the disk
herniation.[12] MED refers to procedures that employ serial dilations and a wider tubular retractor
system into which a rigid functional endoscope is inserted.[12] In this systematic review and meta-analysis, we define return to play rate and return
to play time in athletes undergoing endoscopic diskectomy with either method for lumbar
disk herniations. Further, we assess the difference in preoperative and postoperative
VAS scores.
Materials and Methods
Search Strategy
A systematic literature review regarding endoscopic diskectomy in athletes was performed
using Pubmed-Medline and Ovid-Medline, with the last search in May of 2024. Keywords
searched included athletes, endoscopic surgery, and spine. Due to the exploratory
nature of this study, PROSPERO registration was not performed. A total of 254 papers
were identified on the initial search. For further review 12 papers were selected
by title. Four papers were included in the study after complete analysis of the paper.
Inclusion Criteria
Inclusion criteria were defined using the PICOS format. Population: Athletes with
lumbar disk herniation at all levels of competition. Intervention: Percutaneous or
microendoscopic diskectomy. Comparison group was not necessary for this study. Outcomes:
Proportion of patients returning to play and the number of weeks from the date of
surgery to the return to play date. Postoperative VAS was not a requirement for inclusion
but was extracted when present. Study design: Retrospective review or prospective
cohort studies were eligible for inclusion.
Exclusion Criteria
Case reports and case series with fewer than 10 patients were excluded. Studies were
excluded if they did not report the return to play time or proportion of athletes
who returned to play.
Data Collection
The return to play time and the proportion of athletes who returned to play were extracted.
Herein, return to play denotes the return to full participation at an equal or greater
level compared to before the disk herniation. Patients who returned to play at a lower
level, or did not return to play at all, were not included in the “return to play”
group. Preoperative/postoperative VAS were extracted when present. One reviewer extracted
the data from each study.
Quality/Risk of Bias Assessment
Quality and risk of bias were evaluated across several domains using the Methodological
Index for Non-Randomized Studies (MINORS) tool. Studies were scored 0 (not reported),
1 (inadequately reported), and 2 (adequately reported) regarding a number of domains
measuring methodological quality and potential bias. Two reviewers selected the studies
for inclusion and performed the quality/risk of bias assessment. The PRISMA 2020 guidelines
for reporting systematic reviews were utilized for this study.[13]
Statistical Analysis
All statistical analyses were performed using R software, version 4.3.0 (R Core Team,
2024). Meta-analyses were conducted using the “meta” package (Schwarzer, 2007). A
random effects model was employed to account for variability among studies, with between-study
variance (τ2) estimated using the restricted maximum likelihood (REML) method. Studies were weighted
based on number of participants and precision of collected data. Studies including
outcome measures of interest were included in meta-analysis. Forest plots were generated
to visualize the effect sizes, and heterogeneity was assessed using the I
2 statistic. Where standard deviations (SD) were not reported, they were estimated
by dividing the range by 4.
Results
Study Characteristics
Four studies, involving 119 total patients, were included. Of these studies, one included
high school athletes,[14] one included elite competitive athletes,[15] and two included a combination of both amateur and professional athletes (high school,
collegiate, semi-professional, and professional) ([Table 1]).[16]
[17] All studies included athletes presenting with symptomatic lumbar disk herniation.
All studies included single-level endoscopic diskectomy. Mean follow-up time was greater
than 2 years in all studies. Additional demographic information, including represented
sports, is presented in [Table 1]. PRISMA flow diagram outlining the literature search and study inclusion processes
is presented in [Fig. 1].[13]
Fig. 1 Flow diagram of literature search and study inclusion process.
Table 1
Characteristics of included studies
|
Author
|
Study design
|
n
|
Mean age
|
Preoperative diagnosis
|
Surgery type
|
Number of levels
|
Competition level
|
Sport
|
Study location
|
Mean return to play time (weeks)
|
Return to play rate
|
Mean follow-up period (months)
|
|
Yamaya et al,[14] 2020
|
Case series
|
18
|
17
|
Lumbar disk herniation
|
PELD
|
Single level
|
High school
|
Track and field, wrestling, American football, table tennis, basketball, rugby, softball,
baseball, dance
|
Japan
|
7.0 ± 3.5
|
0.944
|
27
|
|
Yoshimoto et al,[16] 2013
|
Case series
|
25
|
19.4
|
Lumbar disk herniation
|
MED
|
Single level
|
High school
|
Baseball, basketball, badminton, soccer, volleyball, rugby, other
|
Japan
|
10.8 ± 3.8
|
0.826
|
22.8
|
|
Nakamae et al,[17] 2019
|
Case series
|
21
|
22.9
|
Lumbar disk herniation
|
PELD
|
Single level
|
Pro, semi-pro, club, high school, collegiate
|
Football, baseball, volleyball, tennis, track and field, basketball, cycling, boxing,
ping pong
|
Japan
|
9.2 ± 5.5
|
0.950
|
28.1
|
|
Kapetanakis et al,[15] 2021
|
Case series
|
55
|
24.4
|
Lumbar disk herniation
|
PELD
|
Single level
|
Professional athletes
|
Basketball, volleyball, weightlifting, wrestling
|
Greece
|
6.7 ± 0.3
|
1.000
|
24
|
Abbreviations: MED, microendoscopic diskectomy; PELD, percutaneous endoscopic lumbar
diskectomy.
Quality/Risk of Bias Assessment
The MINORS tool was used to assess the quality and risk of bias in the included studies.
All of the included studies adequately reported the aim of the study, the endpoints
assessed, and the follow-up period. Therefore, each study was given a score of “2”
in each of these domains ([Table 2]). None of the included studies mentioned the prospective calculation of the study
size necessary to achieve adequate statistical power, and all studies received a score
of “0” in this domain. Yoshimoto et al somewhat adequately mentioned that three patients
were not included in their return to play analysis because they did not return to
athletics for reasons other than their back or leg pain.[16] Therefore, they received a score of “1” in the loss to follow-up category. All other
studies included all patients in their final analysis, and received scores of “2.”
All studies except for Yamaya et al mentioned the inclusion of consecutive patients.[14] Only Kapetanakis et al conducted a prospective study.[15] Regarding unbiased outcome measures, only Nakamae et al used independent evaluators
while collecting postoperative outcomes data.[17] Therefore, they received a score of “2” for the unbiased endpoint category. All
the other studies discussed their outcome assessment process but did not mention using
independent evaluators, and where therefore given a score of “1.” Overall, all of
the included studies scored in the moderate (9–12) to high (13–16) quality range,
indicating low to moderate risk of bias ([Table 2]). A summary of the risk of bias assessment is provided in [Table 2].
Table 2
Quality/risk of bias assessment for included studies
|
Study
|
Aim
|
Consecutive patients
|
Prospective data
|
Endpoints
|
Unbiased endpoint
|
Follow-up period
|
Loss to follow-up
|
Study size calculation
|
Total (out of 16)
|
|
Yamaya et al,[14] 2020
|
2
|
0
|
0
|
2
|
1
|
2
|
2
|
0
|
10
|
|
Yoshimoto et al,[16] 2013
|
2
|
2
|
0
|
2
|
1
|
2
|
1
|
0
|
10
|
|
Nakamae et al,[17] 2019
|
2
|
2
|
0
|
2
|
2
|
2
|
2
|
0
|
12
|
|
Kapetanakis et al,[15] 2021
|
2
|
2
|
2
|
2
|
1
|
2
|
2
|
0
|
13
|
Return to Play Rate
All four studies reported the mean return to play percentage in athletes following
endoscopic diskectomy.[14]
[15]
[16]
[17] The combined percentage of athletes returning to full participation was 96% (95%
CI: 90%; 100%, I
2 = 49%, t2 = 0.0017, p = 0.12) with a range of 83 to 100%. Aggregated return to play rate is summarized
in [Fig. 2].
Fig. 2 Aggregated return to play rate in athletes following endoscopic diskectomy.
Return to Play Time
All four studies reported the mean return to play time in weeks following endoscopic
diskectomy.[14]
[15]
[16]
[17] The combined mean return to play time was 8.25 weeks (95% CI: 6.51; 10.46, I
2 = 97%, t2 = 0.0508, p < 0.01) with a range of 6.7 to 10.8 weeks.[14]
[15]
[16]
[17] Aggregated return to play time is summarized in [Fig. 3].
Fig. 3 Aggregated return to play time (weeks) in athletes following endoscopic diskectomy.
VAS Outcomes
Two out of the four studies reported mean preoperative and postoperative VAS outcomes
with standard deviations.[15]
[17] The combined mean difference in preoperative and postoperative leg VAS showed a
68.83-point decrease in pain scores following surgery (95% CI: −102.05; 35.61, I
2 = 100%, t2 = 573.493, p < 0.01). The combined mean difference in preoperative and postoperative back VAS
showed a 68.42-point decrease in pain scores following surgery (95% CI: 101.45; 35.40,
I
2 = 100%, t2 = 566.69, p < 0.01). There was very high heterogeneity between studies in preoperative VAS scores.
Aggregated mean differences in VAS back and leg scores are summarized in [Figs. 4] and [5].
Fig. 4 Aggregated mean difference in low back VAS in athletes following endoscopic diskectomy.
Fig. 5 Aggregated mean difference in leg VAS in athletes following endoscopic diskectomy.
Discussion
Endoscopic diskectomy has emerged as a minimally invasive alternative to open diskectomy
for lumbar disk herniation. Prior studies have shown no difference in postoperative
VAS or ODI scores, a decreased length of hospital stay, and reduced return to work
time when compared with open diskectomy in the general population.[7]
[8]
[9]
[10]
[11] These findings are likely the result of reduced soft tissue and paraspinal muscular
damage associated with the minimally invasive approach.[18]
[19] This makes endoscopic diskectomy a potentially attractive alternative to open diskectomy
in athletes who hope to expedite recovery and return to play.
In this meta-analysis, four studies with 119 patients who underwent endoscopic diskectomy
for lumbar disk herniation were analyzed. The combined return to play rate was 96%
by random effects modeling. Kapetanakis et al studied 55 competitive elite athletes
and found the return to play percentage was 100%.[15] Yamaya et al studied only high school athletes and found the return to play rate
was 94%.[14] Yoshimoto et al studied class 3 (high recreational and high school athletes) and
class 4 (college and professional athletes) and found the return to play rate was
83%.[16] Nakamae et al studied both amateur and professional athletes and found the return
to play rate was 95%.[17] There was some heterogeneity between studies regarding return to play rate, likely
due to the inclusion of athletes from different levels of competition. Regardless,
the combined return to play rate in athletes following endoscopic diskectomy is in
the higher end of the 75 to 100% range, reported by a prior systematic review on traditional
open diskectomy in athletes.[6] Based on this data, there is evidence that athletes undergoing endoscopic diskectomy
have a high likelihood of returning to play following surgery.
The combined average return to play time in this study was 8.25 weeks.[14]
[15]
[16]
[17] A prior systematic review on traditional diskectomy in elite athletes found that
the range of return to play time was 2.8 to 8.7 months (11.2–34.8 weeks).[6] By comparison, the combined return to play time is shorter in athletes who underwent
endoscopic diskectomy. These data, when combined with prior studies showing that PELD
decreased length of hospital stay and return to work time compared to traditional
diskectomy in the general population, suggest that there may be a utility for endoscopic
diskectomy in athletes.[7]
[8]
[9]
[10]
[11] With decreased length of hospital stay and postoperative recovery time (as evidenced
by decreased return to work time in the general population and a relatively short
return to play time), athletes may be able to begin rehabilitation earlier, which
could improve return to play time.
There was a high degree of heterogeneity regarding return to play time between the
included studies. Kapetanakis et al found that the return to play time for elite athletes
was 6.7 weeks, which is shorter than the combined return to play time;15 however, Yoshimoto et al found that the return to play time for class 4 athletes
(collegiate and professional) was 11 weeks, which is longer than the combined return
to play time.[16] Likewise, Yamaya et al found the return to play time was 7 weeks for high school
athletes, while Yoshimoto et al found that return to play time was 10.8 weeks in high
school and high recreational athletes.[14]
[16] Even within a level of competition, there is still significant differences in return
to play time. This indicates that the return to play process has more to do with the
specific needs of individual athletes than with the competition level.
Additionally, although all included studies assessed endoscopic diskectomy, the differences
in technique between MED and PELD may account for some of the heterogeneity in return
to play time. Yoshimoto et al were the only investigators who reported outcomes following
MED, and the return to play rate and return to play time were 10.8 weeks and 83% respectively,[16] compared to studies examining PELD, which had return to play time and proportion
ranging from 6.7 to 9.2 weeks and 94 to 100%, respectively.[14]
[15]
[17] Given these results, it appears PELD may be the better surgical approach in athletes
with disk herniations. However, given that only one MED study was included, any assumptions
about the superiority of PELD should be made with caution. Further studies comparing
return to play time in elite and amateur athletes and comparing patients who underwent
MED and PELD would help evaluate the utility of endoscopic diskectomy in athletes
based on level of competition and surgical approach.
Two studies reported postoperative VAS outcomes with standard deviations. Both studies
included athletes who underwent PELD, and the combined mean difference in preoperative
and postoperative VAS was 68.83 for leg pain and 68.42 for back pain; however, there
was significant heterogeneity between the two studies. Nakamae et al studied a combination
of amateur and professional athletes and reported a preoperative leg VAS of 64.3 ± 2.7
and a postoperative leg VAS of 12.4 ± 1.4. They reported a preoperative mean low back
VAS of 62.1 ± 2.2 and a postoperative back VAS of 10.5 ± 1.1.[17] Kapetanakis et al studied elite athletes and reported a preoperative mean leg VAS
of 90.7 ± 8.1 and a postoperative mean leg VAS of 4.9 ± 5.7. They reported a preoperative
mean back VAS of 90.4 ± 8.6 and a mean postoperative back VAS of 5.1 ± 6.1.[15] Though both studies had similar mean postoperative VAS scores, Kapetanakis et al
showed higher preoperative leg and back VAS scores.[15]
[17] It is possible that elite athletes had more severe injuries compared to amateur
athletes due to higher levels of stress on their bodies. Further research is needed
to clarify the effect of endoscopic diskectomy on postoperative VAS in elite and amateur
athletes stratified by level of competition.
Limitations
Potential limitations of this meta-analysis include the small number of included studies,
although this highlights the relative recency and paucity of data regarding endoscopic
diskectomy in athletes. Given the small number of included studies, it was not possible
to examine the literature for publication bias, which limits the conclusions that
can be made from this meta-analysis. Additionally, inconsistent reporting of standard
deviations in the included studies and estimation of these values is a limitation
of our statistical analysis regarding return to play time. Finally, the lack of postoperative
functional metrics, including whether athletes achieved the same level of success
following return to play, limits the clarity regarding whether endoscopic diskectomy
was truly successful in athletes.
Conclusion
Athletes who underwent endoscopic diskectomy for single-level lumbar disk herniation
had a high rate of return to play with a short return to play time when compared to
existing data on traditional open diskectomy. There was a large reduction in VAS postoperatively,
indicating endoscopic diskectomy improves pain in athletes with lumbar disk herniation.
Additional investigation with stratification based on level of athletic competition,
more granular data on sport and position played, and specific endoscopic surgery type
should be performed. Overall, the evidence supports that endoscopic diskectomy is
of benefit to athletes with lumbar disk herniation. However, given the small number
of studies with a paucity of prospective data collection, cautious interpretation
of these findings is required.
