Blog category: Research

Delaying anterior cruciate ligament reconstruction increases the rate and severity of medial chondral injuries.
Cance N, Erard J, Shatrov J, et al.
Bone Joint J. 2023; 105-B(9): 953-960. doi:10.1302/0301-620X.105B9.BJJ-2022-1437.R1

This is an interesting study, where the author authors undertook a retrospective review of over 1000 patients undergoing anterior cruciate ligament reconstruction, looking at the incidence of articular cartilage damage developing in the knee with relation to time, in terms of the length of delay between injury to surgical reconstruction.

What the authors found was that in younger patients, if ACL reconstruction was delayed for more than 12 months, then the likelihood of that patient having articular cartilage damage in their medial compartment by the time of surgery nearly doubled. Importantly, no significant increase in the rate of articular cartilage damage was seen if surgery was undertaken at less than 12 months. Also, the authors found no correlation between surgical delay and articular cartilage damage in the lateral compartment, which seems a bit odd.

What this study seems to say is that delaying ACL surgery by more than 12 months in younger patients is likely to be associated with more damage in the knee, and hence poorer long-term outcomes. The flip side of this, however, is that if surgery is delayed by less than 12 months, then that might not actually cause any significant harm.

This paper gives a significantly more optimistic take on the potential consequences of delaying ACL surgery, compared to a number of previously published papers; but as is so often the case, the literature is somewhat conflicting.

For example,

• Sanders et al. Am J Sports Med 2016; 44(7): 1699 – 1707

in a retrospective study of nearly 1000 patients with ACL tears vs nearly 1000 controls showed that:

• • conservative management of ACL tears was associated with a 500% increased risk of meniscal tears compared to early surgical reconstruction, and a significantly increased risk of future OA, and
  • delayed ACL reconstruction was associated with a 400% increased risk of meniscal tears, and a significantly increased risk of future OA.

• Sri-Ram et al. Bone Joint Journal 2013; 95-B (1): 59 – 64

in a retrospective review of over 5000 ACL reconstructions showed that:

• • a delay in ACL reconstruction > 5 months led to an increased risk of the patient ending up needing surgery for a medial meniscal tear of 200%, and
  • a delay of > 12 months led to an increased risk of 600%.

• Everhart et al. AJSM 2019; 47(8): 1816 – 1824

showed, in a retrospective review of over 600 ACL reconstructions that:

• • delaying surgery by > 8 months was associated with a increased risk of 200% of patients ending up needing a partial meniscectomy, and a 50% reduction in the likelihood of any meniscal tears being repairable.

So, this recent paper by Cance et al. is certainly a lot less pessimistic than some of the previously published evidence in the literature.

The relevance of this to me is that this paper cautiously reinforces the appropriateness of the approach of initially attempting conservative management of ACL tears for most patients (but not for kids, and not for most elite athletes), on the understanding that if the patient fails to do well enough, then surgery can simply be scheduled as / when necessary…  as long as patients with wobbly / unstable knees who do actually need surgical stabilisation are not unduly delayed for too long.

Weaker Quadriceps Muscle Strength With a Quadriceps Tendon Graft Compared With a Patellar or Hamstring Tendon Graft at 7 Months After Anterior Cruciate Ligament Reconstruction
Holmgren et al
American Journal of Sports Medicine 2024 Jan; 52(1): 69-76.
doi: 10.1177/03635465231209442

There are a number of different graft types available replacing a torn anterior cruciate with surgical ACL reconstruction. These include:

• taking some of the hamstring tendons from the patient’s own leg (an ipsilateral hamstring tendon autograft)
• taking the central 1/3 of the patellar tendon from the front of the knee, along with a small section of bone at the top, from the patella, and a small section of bone at the bottom, from the tibial tuberosity (an ipsilateral bone-patellar tendon-bone autograft)
• taking tendons from the patient’s other leg (a contralateral autograft) or
• using a donor tendon (an allograft)

Recently, some surgeons have, instead, started taking a section of the tendon from the distal end of the patient’s quadriceps tendon, and using this instead. This allows a nice big chunky graft; however, does this potentially have any negative consequences?…

In this recently published study by Holmgren et al from Stockholm, Sweden, the authors looked at over 100 patients undergoing ACL reconstruction surgery and they tested the patients’ post-op muscle strength at > 6 months post-op, comparing results between the different types of graft that were used.

Their results showed that the patients who had had a distal quads tendon grafts showed significantly greater muscle weakness with a significantly bigger side-to-side difference in strength between their legs (operated side vs non-operated side).

Importantly, impaired quadriceps muscle strength after ACL surgery is known to be associated with poorer clinical outcomes and a bigger risk of reinjury, with graft rupture.

Take home message:
Just cos it’s new or fashionable, doesn’t mean it’s better! … and this very much applies to ACL surgery, like many other things. There are pros and cons with all the different types of tendon that can be used for replacing / reconstructing a torn ACL in a knee, and no type of graft is ‘perfect’. Importantly, however, it is the patient who is having the surgery and who is receiving the graft, and hence the pros and cons of the different graft types really must be discussed with the patient in advance, and ultimately, it is the patient who should be able to pick and choose what specific type of graft they might want to have implanted into their knee. (Informed consent!)

To find out more about ACL graft options, CLICK HERE

Lateral Meniscal Allograft Transplantation Shows a Long-Term Chondroprotective Effect on Quantitative MRI T2 Mapping at 7 Years’ Minimum Follow-Up
Lee et al.
Arthroscopy 2023, ISSN 0749-8063, https://doi.org/10.1016/j.arthro.2023.09.027.

It’s already well-known and well-documented that meniscal transplantation gives pretty good results – not perfect… but pretty good, with ~90% success at 5-year follow-up and ~80% success at 10-year follow-up [LINK]. However, what is the definition of success???…

We addressed the issue of ‘success’ in our study that was published in 2020:

The results of meniscal allograft transplantation surgery: what is success?
Searle, Asopa, Coleman, McDermott
BMC Musculoskeletal Disorders 2020; 21, 159 (2020). https://doi.org/10.1186/s12891-020-3165-0

However, what are the objective effects of meniscal transplantation on the articular cartilage in that compartment of the patient’s knee?

In a recent study by researchers from South Korea, 31 patients undergoing lateral meniscal allograft transplantation surgery were observed, with a minimum 7-year follow-up (mean 8.9 years). The quality of the articular cartilage in the lateral compartment of each patient’s knee was assessed pre- and post-operatively using quantitative T2 mapping with MRI. The researchers found that meniscal transplantation was actually associated with an improvement in the quality of the patients’ articular cartilage! (Normally, we would be happy to see a slowing down of the progression of a patient’s ‘wear and tear’ in their knee, or we’d even be delighted to see a lack of progression of any degenerative changes. However, to actually see an improvement in the state of these patients’ cartilage is beyond what most meniscal transplant surgeons would normally ever hope for!

Further evidence that meniscal transplantation is an excellent procedure (if performed on the right patient at the right time for the rights reasons and by the right surgeon!).

Find out more about meniscal transplantation: CLICK HERE

Failure rates of common grafts used in ACL reconstructions: a systematic review of studies published in the last decade.
Haybäck et al
Archives of Orthopaedic and Trauma Surgery 2022; 142(11): 3293 – 3299.
LINK

Repeatedly, at important national meetings, I have heard ‘eminent’ orthopaedic surgeons stating that “tendon allografts undoubtedly have a higher failure rate”. But is there any real substance to their seemingly cast-iron confidence?…

A recent review performed by a team at Salzburg University looked at a staggering 152,548 patients with ACL reconstructions, specifically to investigate the rate of graft rupture according to graft types. The findings were:

The authors’ very clear and specific conclusion from this large high-quality study was that there is no statistically significant difference in graft failure rates between any of the different graft types.

So, yet further evidence that directly contradicts what some people seem to say about what type of graft might be best vs which might potentially have a higher failure rate.

Importantly, my personal approach to graft choice for ACL reconstruction is to present my patients with accurate information about the pros and cons of the different graft types available (and all of them have not-insignificant pros and cons, and failure rate is not the only relevant and important metric when it comes to graft choice)… and then it is my patients who make the choice about what type of graft they would like to have used for their surgery.

i.e. Informed Consent and proper Patient Choice

To find out more about the pros and cons of the different graft types available for ACL reconstruction, CLICK HERE

“Need Room to Operate? Partial and Intentional Release of the Knee Medial Collateral Ligament for Medial Meniscal Surgery”
James H. Lubowitz, Michael J. Rossi, Jefferson C. Brand
Arthroscopy 2020; 36(6): 1487-1488

The lead editorial article in June’s edition of the Arthroscopy journal focusses entirely on the technique of partial release of the medial collateral ligament at the time of arthroscopy. Perforating the MCL with multiple holes percutaneously with a needle while appying a valgus stress creates a partial release of the ligament that is akin to a ‘sprain’ of the ligament. This opens up the joint into just very slight valgus, thereby opening up the medial comparment by a few additional millimetres.

This technique takes no more than 1 – 2 minutes, and it is easy, with extremely low risks of any potential morbidity. It allows much clearer visualisation and access to the posterior aspect of the medial compartment at arthroscopy, allowing proper and full evaluation of tears to the posterior horn of the medial meniscus and proper surgical treatment of whatever pathology might be found in this area. Importantly, it also drastically reduces the potential risk of accidental iatrogenic articular cartilage damage whilst trying to access a tight space at the back of the medial compartment.

The partially released ligament heals up absolutely fine on its own (just like a minor MCL sprain does), and research has shown that it does not cause any residual laxity in the ligament or any other significant adverse consequences.

The terms that is often used for this technique is ‘pie-crusting of the MCL’, and it is something that I use on a not-infrequent basis in my practice, for example for medial meniscal repairs or meniscal trimming, but particularly for more technically demanding procedures such as ramp lesion repairs, meniscal root avulsion repairs and meniscal allograft transplantation. This technique should be a routine part of the toolkit of every soft tissue knee surgeon!

CLICK HERE to read more…