Intraosseous Morphine After Total Knee Arthroplasty — No Additional Benefit

Polish version

Adding 10 mg of morphine to an intraosseous injection during primary total knee arthroplasty did not reduce pain or opioid consumption during the first 14 days after surgery. This is the practical finding of a double-blind randomised trial published in the 19 August 2026 issue of The Journal of Bone and Joint Surgery; the paper had been available online since 21 April 2026.

Why is this study clinically interesting?

Multimodal analgesic protocols are increasingly used in total knee arthroplasty to control pain while limiting opioid exposure. One approach is intraosseous drug delivery, intended to produce a high local concentration in the operative region. Intraosseous administration has established uses for selected antibiotics, but that does not mean every drug given by this route will provide a clinically meaningful additional effect.

The study by Pekas and colleagues addressed a specific question: does adding morphine to an intraosseous injection improve pain control after TKA beyond a contemporary multimodal analgesic protocol?

Study question and methodology

The prospective randomised trial enrolled 100 patients undergoing elective primary total knee arthroplasty and used double blinding. The final analysis included 88 patients; mean age was 69.1 years.

All patients received spinal anaesthesia with intravenous sedation and a surgeon-performed adductor canal block. Both groups received 500 mg of vancomycin in 110 mL of normal saline by the intraosseous route. In the intervention group, 10 mg of morphine was added to that solution; the control group received an otherwise identical injection without morphine.

For 14 days after surgery, patients repeatedly reported pain intensity, opioid use converted to morphine equivalents, and nausea and vomiting. Immediate postoperative pain and opioid requirements, as well as patient-reported outcomes, were also assessed.

Results

There were no between-group differences in daily pain at any time point during the 14-day follow-up (p = 0.969). Daily opioid consumption also did not differ (p = 0.377), and total and weekly opioid consumption remained similar (p ≥ 0.878).

In practical terms, within the protocol studied, 10 mg of intraosseous morphine provided no measurable additional analgesic benefit.

Clinical interpretation for an orthopaedic surgeon

The negative result is clinically relevant. Adding another component to a perioperative pathway is justified only if the benefit outweighs the additional cost, risk and complexity. In this trial, no such benefit was demonstrated for intraosseous morphine.

The finding should nevertheless be interpreted in the context of effective baseline analgesia. Patients received spinal anaesthesia, intravenous sedation and an adductor canal block. With such a regimen, the scope for demonstrating a small incremental benefit may have been limited. That does not change the principal practical conclusion: this study provides no basis for routinely adding morphine to the intraosseous injection in TKA.

Limitations

• The final analysis included 88 of the 100 randomised patients.
• Pain and opioid use were followed for only the first 14 postoperative days.
• The trial evaluated one specific 10 mg morphine dose within one perioperative protocol; it does not answer questions about other doses or drug combinations.
• The study population was relatively demographically homogeneous, which may limit generalisability.
• Both groups received intraosseous vancomycin, so the study isolates the effect of added morphine rather than comparing the intraosseous route itself with other routes of drug administration.

What may change in practice—and what the study does not prove

The results argue against routinely including intraosseous morphine as an additional analgesic component in primary TKA when a similar multimodal protocol is already being used. This supports simplifying pathways in which an added drug does not provide a demonstrable benefit.

The trial does not show that the intraosseous route is ineffective in general. It did not assess the efficacy of intraosseous antibiotics or other drugs, and it does not resolve the value of other local analgesic strategies. Nor can it be used to conclude that morphine has no role in pain management after TKA—the intervention tested was specifically intraoperative intraosseous administration at the stated dose.

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Reference

Pekas DR, Adrados M, Lee MM, et al. Effectiveness of Intraosseous Morphine for Pain Control in Total Knee Arthroplasty: A Double-Blinded, Randomized Trial. J Bone Joint Surg Am. 2026;108(16):1249-1255. DOI: 10.2106/JBJS.25.01037. PubMed: PMID 42013190.

Content prepared by: Tomasz Poboży - orthopaedic surgeon.